The AZEK Company Inc. (AZEK) 10-Q 10 May 22 2022 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Mar. 31, 2022	Apr. 29, 2022
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2022
Document Period End Date	Mar. 31, 2022
Current Fiscal Year End Date	--09-30
Entity Registrant Name	AZEK Co Inc.
Entity Central Index Key	0001782754
Entity File Number	001-39322
Entity Tax Identification Number	90-1017663
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Incorporation, State or Country Code	DE
Entity Emerging Growth Company	false
Entity Address, Address Line One	1330 W Fulton Street, Suite 350
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60607
City Area Code	877
Local Phone Number	275-2935
Title of 12(b) Security	Class A Common Stock, par value $0.001 per share
Trading Symbol	AZEK
Security Exchange Name	NYSE
Common Class A [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		155,155,235
Common Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		100

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Current assets:
Cash and cash equivalents	$ 25,812	$ 250,536
Trade receivables, net of allowances	171,685	77,316
Inventories	299,160	188,888
Prepaid expenses	18,203	14,212
Other current assets	5,991	1,446
Total current assets	520,851	532,398
Property, plant and equipment - net	474,340	391,012
Goodwill	987,440	951,390
Intangible assets - net	260,128	242,572
Other assets	76,721	70,462
Total assets	2,319,480	2,187,834
Current liabilities:
Accounts payable	76,228	69,474
Accrued rebates	31,723	44,339
Accrued interest	46	72
Accrued expenses and other liabilities	65,586	56,522
Total current liabilities	173,583	170,407
Deferred income taxes	61,505	46,371
Long-term debt—less current portion	505,284	464,715
Other non-current liabilities	86,074	79,177
Total liabilities	826,446	760,670
Commitments and contingencies (See Note 17)
Stockholders' equity:
Preferred stock, $0.001 par value; 1,000,000 shares authorized and no shares issued or outstanding at March 31, 2022 and September 30, 2021, respectively
Additional paid‑in capital	1,628,581	1,615,236
Accumulated deficit	(135,702)	(188,227)
Total stockholders' equity	1,493,034	1,427,164
Total liabilities and stockholders' equity	2,319,480	2,187,834
Common Class A [Member]
Stockholders' equity:
Common stock	$ 155	$ 155

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2022	Sep. 30, 2021
Preferred stock, par value per share	$ 0.001	$ 0.001
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Class A [Member]
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	1,100,000,000	1,100,000,000
Common stock, shares issued	155,108,627	154,866,313
Common stock, shares outstanding	155,108,627	154,866,313
Common Class B [Member]
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	100	100
Common stock, shares outstanding	100	100

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net sales	$ 396,255	$ 293,121	$ 655,963	$ 505,399
Cost of sales	273,795	195,272	444,894	334,572
Gross profit	122,460	97,849	211,069	170,827
Selling, general and administrative expenses	70,822	60,155	133,991	113,602
Other general expenses		1,149		1,149
Operating income (loss)	51,638	36,545	77,078	56,076
Other expenses:
Interest expense	4,010	6,348	8,158	12,374
Total other expenses	4,010	6,348	8,158	12,374
Income (loss) before income taxes	47,628	30,197	68,920	43,702
Income tax expense (benefit)	11,810	7,557	16,395	10,914
Net income (loss)	$ 35,818	$ 22,640	$ 52,525	$ 32,788
Net income (loss) per common share - basic	$ 0.23	$ 0.15	$ 0.34	$ 0.21
Net income (loss) per common share - diluted	$ 0.23	$ 0.14	$ 0.34	$ 0.21
Comprehensive income (loss)	$ 35,818	$ 22,640	$ 52,525	$ 32,788
Weighted-average common shares outstanding - basic and diluted
Basic	154,661,277	153,509,612	154,551,589	153,366,516
Diluted	156,121,476	156,747,514	156,560,502	156,377,902

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Adoption of ASU [Member]	Common Stock [Member]Common Class A [Member]	Common Stock [Member]Common Class B [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member]Adoption of ASU [Member]
Beginning balance at Sep. 30, 2020	$ 1,303,888		$ 155		$ 1,587,208	$ (283,475)
Beginning balance (in shares) at Sep. 30, 2020			154,637,240	100
Net income (loss)	32,788					32,788
Stock-based compensation	9,931				9,931
Exercise of vested stock options	2,953				2,953
Exercise of vested stock options (in shares)			123,993
Cancellation of restricted stock awards			(21,995)
IPO costs	(210)				(210)
Adoption of ASU 2016-02		$ 2,098					$ 2,098
Ending balance at Mar. 31, 2021	1,351,448		$ 155		1,599,882	(248,589)
Ending balance (in shares) at Mar. 31, 2021			154,739,238	100
Beginning balance at Dec. 31, 2020	1,321,166		$ 155		1,592,240	(271,229)
Beginning balance (in shares) at Dec. 31, 2020			154,735,617	100
Net income (loss)	22,640					22,640
Stock-based compensation	7,052				7,052
Exercise of vested stock options	590				590
Exercise of vested stock options (in shares)			25,616
Cancellation of restricted stock awards			(21,995)
Ending balance at Mar. 31, 2021	1,351,448		$ 155		1,599,882	(248,589)
Ending balance (in shares) at Mar. 31, 2021			154,739,238	100
Beginning balance at Sep. 30, 2021	1,427,164		$ 155		1,615,236	(188,227)
Beginning balance (in shares) at Sep. 30, 2021			154,866,313	100
Net income (loss)	52,525					52,525
Stock-based compensation	8,851				8,851
Exercise of vested stock options	4,923				4,923
Exercise of vested stock options (in shares)			214,041
Cancellation of restricted stock awards			(10,573)
Issuance of common stock under employee stock plan, net of shares withheld for taxes	(429)				(429)
Issuance of common stock under employee stock plan, net of shares withheld for taxes (in shares)			38,846
Ending balance at Mar. 31, 2022	1,493,034		$ 155		1,628,581	(135,702)
Ending balance (in shares) at Mar. 31, 2022			155,108,627	100
Beginning balance at Dec. 31, 2021	1,451,151		$ 155		1,622,516	(171,520)
Beginning balance (in shares) at Dec. 31, 2021			155,032,377	100
Net income (loss)	35,818					35,818
Stock-based compensation	4,881				4,881
Exercise of vested stock options	1,613				1,613
Exercise of vested stock options (in shares)			70,149
Cancellation of restricted stock awards			(6,174)
Issuance of common stock under employee stock plan, net of shares withheld for taxes	(429)				(429)
Issuance of common stock under employee stock plan, net of shares withheld for taxes (in shares)			12,275
Ending balance at Mar. 31, 2022	$ 1,493,034		$ 155		$ 1,628,581	$ (135,702)
Ending balance (in shares) at Mar. 31, 2022			155,108,627	100

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities:
Net income (loss)	$ 52,525	$ 32,788
Adjustments to reconcile net income (loss) to net cash flows provided by (used in) operating activities:
Depreciation	31,680	24,366
Amortization of intangibles	25,444	25,183
Non-cash interest expense	2,373	1,996
Non-cash lease expense	(68)	39
Deferred income tax (benefit) provision	15,132	8,710
Non-cash compensation expense	11,773	9,931
Loss (gain) on disposition of property	425	298
Changes in certain assets and liabilities:
Trade receivables	(90,571)	(57,578)
Inventories	(98,616)	(36,429)
Prepaid expenses and other currents assets	(8,677)	(2,111)
Accounts payable	12,213	8,239
Accrued expenses and interest	(22,294)	(8,461)
Other assets and liabilities	1,118	1,115
Net cash provided by (used in) operating activities	(67,543)	8,086
Investing activities:
Purchases of property, plant and equipment	(113,995)	(72,735)
Proceeds from disposition of fixed assets	497	32
Acquisitions, net of cash acquired	(86,935)
Net cash provided by (used in) investing activities	(200,433)	(72,703)
Financing activities:
Proceeds under revolving credit facility	40,000
Payment of debt issuance costs		(938)
Repayments of finance lease obligations	(1,242)	(883)
Exercise of vested stock options	4,923	2,953
Payments of initial public offering related costs		(210)
Cash paid for shares withheld for taxes	(429)
Net cash provided by (used in) financing activities	43,252	922
Net increase (decrease) in cash and cash equivalents	(224,724)	(63,695)
Cash and cash equivalents – Beginning of period	250,536	215,012
Cash and cash equivalents – End of period	25,812	151,317
Supplemental cash flow disclosure:
Cash paid for interest, net of amounts capitalized	5,792	8,645
Cash paid for income taxes, net	5,484	2,341
Supplemental non-cash investing and financing disclosure:
Capital expenditures in accounts payable at end of period	11,976	4,420
Right-of-use operating and finance lease assets obtained in exchange for lease liabilities	$ 10,208	$ 9,157

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	6 Months Ended
	Mar. 31, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Summary of Significant Accounting Policies	1. ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES a. Organization The AZEK Company Inc. (the “Company”, “we”, “us” or “our”) is a Delaware corporation that holds all of the limited liability company interests in CPG International LLC, the entity which directly and indirectly holds all of the equity interests in the operating subsidiaries. The Company is an industry-leading designer and manufacturer of beautiful, low-maintenance and environmentally sustainable building products for residential, commercial and industrial markets. The Company’s products include decking, railing, trim, porch, moulding, pavers, bathroom and locker systems, as well as extruded plastic sheet products and other non-fabricated products for special applications in industrial markets. The Company operates in various locations throughout the United States. The Company’s residential products are primarily branded under the brand names AZEK, TimberTech, VERSATEX, ULTRALOX and StruXure, while the commercial products are branded under the brand names Celtec, Playboard, Seaboard, Flametec, Designboard, Cortec, Sanatec, Scranton Products, Aria Partitions, Eclipse Partitions, Hiny Hiders, Tufftec Lockers and Duralife Lockers. Secondary Offerings On January 26, 2021, the Company completed an offering of 23,000,000 shares of Class A common stock, par value $0.001 per share, including the exercise in full by the underwriters of their option to purchase up to 3,000,000 additional shares of Class A common stock, at a public offering price of $40.00 per share. The shares were sold by certain of the Selling Stockholders. The Company did not receive any of the proceeds from the sale of the shares by those Selling Stockholders. In connection with the offering the Company incurred approximately $1.2 million in expenses. On June 1, 2021, the Company completed an offering of 17,250,000 shares of Class A common stock, par value $0.001 per share, including the exercise in full by the underwriters of their option to purchase up to 2,250,000 additional shares of Class A common stock, at a public offering price of $43.50 per share. The shares were sold by certain of the Selling Stockholders. The Company did not receive any of the proceeds from the sale of the shares by those Selling Stockholders. In connection with the offering the Company incurred approximately $1.1 million in expenses. b. Summary of Significant Accounting Policies Basis of Presentation The Company operates on a fiscal year ending September 30. The accompanying unaudited Condensed Consolidated Financial Statements and notes have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information, and in management’s opinion, includes all adjustments, consisting of only normal recurring adjustments, necessary for the fair statement of the Company’s financial position, its results of operations and cash flows for the interim periods presented. The results of operations for the three and six months ended March 31, 2022 and the cash flows for the six months ended March 31, 2022 are not necessarily indicative of the results to be expected for the full fiscal year or any other period. The Company’s financial condition and results of operations are being, and are expected to continue to be affected by the current COVID-19 public health pandemic. The economic effects of the COVID-19 pandemic will likely continue to affect demand for the Company’s products in the foreseeable future. Although management has implemented measures to mitigate any impact of the COVID-19 pandemic on the Company’s business, financial condition and results of operations, these measures may not fully mitigate the impact of the COVID-19 pandemic on the Company’s business, financial condition and results of operations. Management cannot predict the degree to, or the period over, which the Company will be affected by the COVID-19 pandemic and resulting governmental and other measures. The accompanying unaudited Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and notes thereto included in the Company’s 2021 Form 10-K. The Condensed Consolidated Balance Sheet as of September 30, 2021 was derived from the audited financial statements at that date. There have been no material changes in the Company’s significant accounting policies from those that were disclosed in the 2021 Form 10-K, except as noted below. Revision of Previously Reported Financial Information In connection with our retroactive adoption of ASC 842 as of October 1, 2020, quarterly amounts presented in our prior Form 10-Q were revised. The impact of the adjustments was immaterial to the Consolidated Financial Statements. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Significant estimates include revenue recognition, reserves for excess inventory, inventory obsolescence, product warranties, customer rebates, stock-based compensation, litigation, income taxes, contingent consideration, goodwill and intangible asset valuation and accounting for long-lived assets. Management’s estimates and assumptions are evaluated on an ongoing basis and are based on historical experience, current conditions and available information. Actual results may differ from estimated amounts. Estimates are revised as additional information becomes available. Accounting Policies Refer to the Company’s 2021 Form 10-K for a discussion of the Company’s accounting policies, as updated below and for recently adopted accounting standards. Research and Development Costs Research and development costs primarily relate to new product development, product claims support and manufacturing process improvements. Such costs are expensed as incurred and are included in “Selling, general and administrative expenses” within the Condensed Consolidated Statements of Comprehensive Income (Loss). Total research and development expenses were $2.3 million and $1.7 million, respectively, for the three months ended March 31, 2022 and 2021, and $4.3 million and $3.6 million, respectively, for the six months ended March 31, 2022 and 2021. Recently Adopted Accounting Pronouncements On October 1, 2020, the Company adopted ASU No. 2016-02, Leases (Topic 842) On October 1, 2021, the Company adopted ASU No. 2019-12, Income Taxes (Topic 740)—Simplifying the Accounting for Income Taxes

Revenue

Revenue	6 Months Ended
	Mar. 31, 2022
Revenue From Contract With Customer [Abstract]
Revenue	2. REVENUE The Company recognizes revenues when control of the promised goods is transferred to the Company’s customers in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods, at a point in time, when shipping occurs. The Company also engages in customer rebates, which are recorded in “Net sales” in the Condensed Consolidated Statements of Comprehensive Income (Loss) and in “Accrued rebates” and “Trade receivables” in the Condensed Consolidated Balance Sheets. The Company recorded accrued rebates of $31.7 million and $22.9 million as of March 31, 2022 and 2021, respectively, and contra trade receivables of $8.4 million and $4.9 million as of March 31, 2022 and 2021, respectively. The rebate activity was as follows (in thousands): Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Beginning balance $ 53,841 $ 38,819 $ 47,648 $ 32,679 Rebate expense 30,402 20,539 46,552 34,212 Rebate payments (44,097 ) (31,567 ) (54,054 ) (39,100 ) Ending balance $ 40,146 $ 27,791 $ 40,146 $ 27,791 The Company records deferred revenue when cash payments are received or due in advance of the Company’s performance.

Business Combinations

Business Combinations	6 Months Ended
	Mar. 31, 2022
Business Combinations [Abstract]
Business Combinations	3. BUSINESS COMBINATIONS On November 30, 2021, the Company acquired 100% of a regional recycler in the Midwest, for a total purchase price of approximately $4.2 million, subject to customary post-closing working capital adjustments. The regional recycler is a provider of full-service recycled material processing, sourcing, logistical support and scrap management programs. The Company financed the acquisition with cash on hand. On December 29, 2021, the Company acquired 100% of StruXure Outdoor, LLC, a Georgia limited liability company (“StruXure Outdoor”), for a total purchase price of approximately $84.1 million, subject to customary post-closing working capital adjustments. StruXure Outdoor is located in Dahlonega, Georgia and manufactures customizable outdoor pergolas and cabanas. The Company financed the acquisition with cash on hand. The acquisitions were accounted for as business combinations under Accounting Standards Codification (“ASC”) 805 Business Combinations The following table represents the preliminary allocation of assets acquired and liabilities assumed on the acquisition date for both acquisitions as of March 31, 2022 (in thousands): (US dollars in thousands) Total Cash and cash equivalents $ 1,410 Trade receivables 3,798 Inventories 11,655 Other current assets 95 Property and equipment 4,618 Intangible assets 43,000 Accounts payable (3,110 ) Accrued expenses and other liabilities (9,171 ) Total identifiable assets 52,295 Goodwill 36,050 Net assets acquired/total consideration 88,345 Less: cash acquired (1,410 ) Total consideration net of cash acquired $ 86,935 As of the acquisition dates, total intangible assets and goodwill amounted to $79.1 million, comprised of $23.0 million related to customer relationships, $10.0 million related to proprietary knowledge and $10.0 million related to trademarks, as well as $36.1 million in goodwill. It is expected that $36.1 million of the goodwill is deductible for tax purposes. The estimated useful life for customer relationships and trademarks is 15 years

Inventories

Inventories	6 Months Ended
	Mar. 31, 2022
Inventory Disclosure [Abstract]
Inventories	4. INVENTORIES Inventories are valued at the lower of cost or net realizable value, and are reduced for slow-moving and obsolete inventory. The inventories cost is recorded at standard cost, which approximates actual cost, on a first-in first-out “FIFO”) basis. Inventories consisted of the following (in thousands): in thousands March 31, 2022 September 30, 2021 Raw materials $ 74,120 $ 46,046 Work in process 37,826 27,278 Finished goods 187,214 115,564 Total inventories $ 299,160 $ 188,888

Property, Plant and Equipment -

Property, Plant and Equipment - Net	6 Months Ended
	Mar. 31, 2022
Property Plant And Equipment [Abstract]
Property, Plant and Equipment - Net	5. PROPERTY, PLANT AND EQUIPMENT—NET Property, plant and equipment – net consisted of the following (in thousands): March 31, 2022 September 30, 2021 Land and improvements $ 3,222 $ 2,812 Buildings and improvements 80,397 73,227 Manufacturing equipment 462,924 405,611 Computer equipment 24,866 23,915 Furniture and fixtures 7,124 6,018 Vehicles 830 604 Total property and equipment 579,363 512,187 Construction in progress 173,929 129,886 753,292 642,073 Accumulated depreciation (278,952 ) (251,061 ) Total property and equipment – net $ 474,340 $ 391,012 Depreciation expense was approximately $16.5 million and $12.7 million in the three months ended March 31, 2022 and 2021, respectively, and $31.7 million and $24.4 million in the six months ended March 31, 2022 and 2021, respectively. During the three months ended March 31, 2022 and 2021, $1.2 million and $0.5 million of interest was capitalized, respectively, and during the six months ended March 31, 2022 and 2021, $2.3 million and $0.9 million of interest was capitalized, respectively.

Goodwill and Intangible Assets

Goodwill and Intangible Assets - Net	6 Months Ended
	Mar. 31, 2022
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets - Net	6. GOODWILL AND INTANGIBLE ASSETS—NET Goodwill Goodwill consisted of the following (in thousands): Residential Commercial Total Goodwill as of September 30, 2021 $ 911,001 $ 40,389 $ 951,390 Acquisitions 36,050 — 36,050 Goodwill as of March 31, 2022 $ 947,051 $ 40,389 $ 987,440 Accumulated impairment losses as of September 30, 2021 — 32,200 32,200 Accumulated impairment losses as of March 31, 2022 $ — $ 32,200 $ 32,200 Intangible assets, net The Company did not have any indefinite lived intangible assets other than goodwill as of March 31, 2022 and September 30, 2021. Finite-lived intangible assets consisted of the following (in thousands): March 31, 2022 Lives in Years Gross Carrying Value Accumulated Amortization Net Carrying Value Proprietary knowledge 10 - 15 $ 299,300 $ (225,969 ) $ 73,331 Trademarks 5 - 20 229,340 (143,911 ) 85,429 Customer relationships 15 - 19 169,552 (70,800 ) 98,752 Patents 10 7,000 (4,518 ) 2,482 Other intangibles 3 - 15 4,076 (3,942 ) 134 Total intangible assets $ 709,268 $ (449,140 ) $ 260,128 September 30, 2021 Lives in Years Gross Carrying Value Accumulated Amortization Net Carrying Value Propriety knowledge 10 — 15 $ 289,300 $ (216,283 ) $ 73,017 Trademarks 5 — 20 223,840 (139,631 ) 84,209 Customer relationships 15 — 19 146,670 (64,412 ) 82,258 Patents 10 7,000 (4,105 ) 2,895 Other intangible assets 3 — 15 4,076 (3,883 ) 193 Total intangible assets $ 670,886 $ (428,314 ) $ 242,572 Amortization expense was $12.6 million and $12.5 million in the three months ended March 31, 2022 and 2021, respectively and $25.4 million and $25.2 million in the six months ended March 31, 2022 and 2021, respectively. As of March 31, 2022, the remaining weighted-average amortization period for acquired intangible assets was 12.3 years.

Composition of Certain Balance

Composition of Certain Balance Sheet Accounts	6 Months Ended
	Mar. 31, 2022
Composition Of Certain Balance Sheet Accounts Disclosure [Abstract]
Composition of Certain Balance Sheet Accounts	7. COMPOSITION OF CERTAIN BALANCE SHEET ACCOUNTS Allowance for Doubtful Accounts Allowance for doubtful accounts consisted of the following (in thousands): Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Beginning balance $ 1,074 $ 1,338 $ 1,109 $ 1,332 Provision 98 149 63 155 Bad debt write-offs — — — — Ending balance $ 1,172 $ 1,487 $ 1,172 $ 1,487 Accrued Expenses and Other Liabilities Accrued expenses consisted of the following (in thousands): March 31, 2022 September 30, 2021 Employee related liabilities $ 24,590 $ 32,996 Customer deposits 10,676 — Lease liability - operating 5,018 3,906 Marketing 3,847 3,421 Warranty 3,218 2,992 Construction in progress 8,421 4,068 Professional fees 1,737 2,296 Freight 2,211 2,292 Lease liability - finance 1,217 71 Other 4,651 4,480 Total accrued expenses and other current liabilities $ 65,586 $ 56,522

Debt

Debt	6 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Debt	8. DEBT Debt consisted of the following (in thousands): March 31, 2022 September 30, 2021 Term Loan due May 5, 2024 — LIBOR + 2.50% (3.25% at both March 31, 2022 and September 30, 2021) $ 467,654 $ 467,654 Revolving Credit Facility through March 31, 2026 - LIBOR + 1.25% (2.25% at March 31, 2022) 40,000 — Total 507,654 467,654 Less unamortized deferred financing costs (2,117 ) (2,625 ) Less unamortized original issue discount (253 ) (314 ) Less current portion — Long-term debt—less current portion and unamortized deferred financing costs $ 505,284 $ 464,715 Term Loan Agreement The term loan agreement, as amended and restated from time to time (the “Term Loan Agreement”), is a first lien term loan originally entered into on September 30, 2013 by the Company’s wholly-owned subsidiary, CPG International LLC (as successor-in-interest to CPG Merger Sub LLC), as the initial borrower with a syndicate of lenders party thereto. As of March 31, 2022 and September 30, 2021, CPG International LLC had $467.7 million outstanding under the Term Loan Agreement. The Term Loan Agreement matures on May 5, 2024. The obligations under the Term Loan Agreement are secured by a first priority security interest in the membership interests of CPG International LLC owned by the Company and substantially all of the present and future assets of the borrowers and guarantors named therein including equity interests of their domestic subsidiaries, subject to certain exceptions, (the “Term Loan Priority Collateral”) and a second priority lien on current assets. The obligations under the Term Loan Agreement are guaranteed by the Company and the wholly owned domestic subsidiaries of CPG International LLC other than certain immaterial subsidiaries and other excluded subsidiaries. On February 2, 2021, the Company entered into an amendment to the Term Loan Agreement. The amendment effected through reducing (i) the ABR floor by 25 basis points from 2.0% to 1.75%, (ii) the Adjusted LIBOR Rate floor by 25 basis points from 1.0% to 0.75% and (iii) the Applicable Margin with respect to any Effective Date Term Loans, by up to 125 basis points from 3.75% to 2.50% in the case of any Eurocurrency Loan and by up to 125 basis points from 2.75% to 1.50% in the case of any ABR Loan. The Applicable Margin may be reduced by a further 25 basis points in respect of both Eurocurrency Loans and ABR Loans during any period that the Borrower maintains specified public corporate family ratings. Following the amendment, the Term Loan Agreement provides for interest on outstanding principal thereunder at a fluctuating rate, at CPG International LLC’s option, for (i) alternative base rate (“ABR”) borrowings, the highest of (a) the Federal Funds Rate as of such day plus 50 basis points, (b) the prime commercial lending rate announced as of such day by the Administrative Agent as defined in the Term Loan Agreement, as the “prime rate” as in effect on such day and (c) the LIBOR as of such day for a deposit in U.S. dollars with a maturity of one month plus 100 basis points, provided that in no event shall the ABR be less than 175 basis points, plus the applicable margin of 150 basis points per annum; or (ii) for Eurocurrency borrowings, the highest of (a) the LIBOR in effect for such interest period divided by one, minus the statutory reserves applicable to such Eurocurrency borrowing, if any, and (b) 75 basis points, plus the applicable margin of 250 basis points per annum. As of March 31, 2022, and September 30, 2021, unamortized deferred financing fees related to the Term Loan Agreement were $2.1 million and $2.6 million, respectively. The Term Loan Agreement may be voluntarily prepaid in whole, or in part, in each case without premium or penalty (other than the Prepayment Premium (as defined in the Term Loan Agreement), if applicable), subject to certain customary conditions. The Term Loan Agreement requires mandatory prepayments of the term loans thereunder from certain debt issuances, certain asset dispositions (subject to certain reinvestment rights) and a percentage of excess cash flow (subject to step-downs upon CPG International LLC achieving certain leverage ratios). At September 30, 2021, no excess cash flow payment was required based on the current leverage ratio. CPG International LLC is required to repay the outstanding principal amount under the Term Loan Agreement in quarterly installments equal to 0.25253% of the aggregate principal amount under the Term Loan Agreement outstanding on the amendment date of June 18, 2018 and such quarterly payments may be reduced as a result of prepayments. Based on prepayments maturity. The Company’s next scheduled principal payment on the term loan is due in fiscal year 2024. The Term Loan Agreement restricts payments of dividends unless certain conditions are met, as defined in the Term Loan Agreement. On April 28, 2022, the Company entered into a new first lien term loan credit agreement (the “2022 Term Loan Agreement”), the proceeds of which were applied, among other uses, to prepay the obligations of the Term Loan Agreement in full. See Note 19 to the Condensed Consolidated Financial Statements for a discussion of the 2022 Term Loan Agreement. Revolving Credit Facility CPG International LLC has also entered into a revolving credit facility, as amended and restated from time to time (the “Revolving Credit Facility”), with certain of our direct and indirect subsidiaries and certain lenders party thereto. The Revolving Credit Facility provides for maximum aggregate borrowings of up to $150.0 million, subject to an asset-based borrowing base. The borrowing base is limited to a set percentage of eligible accounts receivable and inventory, less reserves that may be established by the administrative agent and the collateral agent in the exercise of their reasonable credit judgment. CPG International LLC had $40.0 million and $0.0 million outstanding borrowings under the Revolving Credit Facility as of March 31, 2022 and September 30, 2021, respectively. In addition, CPG International LLC had $2.8 million and $3.3 million of outstanding letters of credit held against the Revolving Credit Facility as of March 31, 2022 and September 30, 2021, respectively. CPG International LLC had approximately $107.2 million available under the borrowing base for future borrowings as of March 31, 2022. CPG International LLC also has the option to increase the commitments under the Revolving Credit Facility by up to $100.0 million, subject to certain conditions. On March 31, 2021, CPG International LLC amended the Revolving Credit Facility, resulting in a repricing and extension thereof. Pursuant to such amendment, the interest rate has been reduced by 25 basis points to (i) for ABR borrowings, the highest of (a) the Federal Funds Rate plus 50 basis points, (b) the prime rate and (c) the LIBOR as of such date for a deposit in U.S. dollars with a maturity of one month plus 100 basis points, plus, in each case, a spread of 25 to 75 basis points, based on average historical availability, or (ii) for Eurocurrency borrowings, adjusted LIBOR plus a spread of 125 to 175 basis points, based on average historical availability. The maturity date for the Revolving Credit Facility was extended from May 9, 2022 to the earlier of March 31, 2026 and the date that is 91 days prior to the maturity of the Term Loan Agreement or any permitted refinancing thereof. Deferred financing costs, net of accumulated amortization, related to the Revolving Credit Facility at March 31, 2022 and September 30, 2021 were $1.0 million and $1.2 million, respectively. A “commitment fee” accrues on any unused portion of the commitments under the Revolving Credit Facility during the preceding three calendar month period. If the average daily used percentage is greater than 50%, the commitment fee equals 25 basis points, and if the average daily used percentage is less than or equal to 50%, the commitment fee equals 37.5 basis points. The commitment fees were $0.1 million and $0.1 million for the three months ended March 31, 2022 and 2021, respectively, and $0.2 million and $0.3 million in the six months ended March 31, 2022 and 2021, respectively. The obligations under the Revolving Credit Facility are guaranteed by the Company and its wholly owned domestic subsidiaries other than certain immaterial subsidiaries and other excluded subsidiaries. The obligations under the Revolving Credit Facility are secured by a first priority security interest in substantially all of the accounts receivable, inventory, deposit accounts, securities accounts and cash assets of the Company, CPG International LLC and the subsidiaries of CPG International LLC that are guarantors under the Revolving Credit Facility, and the proceeds thereof (subject to certain exceptions) (the “Revolver Priority Collateral”), plus a second priority security interest in all of the Term Loan Priority Collateral. The Revolving Credit Facility may be voluntarily prepaid in whole, or in part, in each case without premium or penalty. CPG International LLC is also required to make mandatory prepayments (i) when aggregate borrowings exceed commitments or the applicable borrowing base and (ii) during “cash dominion,” which occurs if (a) the availability under the Revolving Credit Facility is less than the greater of (i) $12.5 million and (ii) 10% of the lesser of (x) $150.0 million and (y) the borrowing base, for five consecutive business days or (b) certain events of default have occurred and are continuing. The Revolving Credit Facility contains affirmative covenants that are customary for financings of this type, including allowing the Revolver Administrative Agent to perform periodic field exams and appraisals to evaluate the borrowing base. The Revolving Credit Facility contains various negative covenants, including limitations on, subject to certain exceptions, the incurrence of indebtedness, the incurrence of liens, dispositions, investments, acquisitions, restricted payments, transactions with affiliates, as well as other negative covenants customary for financings of this type. The Revolving Credit Facility also includes a financial maintenance covenant, applicable only when the excess availability is less than the greater of (i) 10% of the lesser of the aggregate commitments under the Revolving Credit Facility and the borrowing base, and (ii) $12.5 million. In such circumstances, CPG International LLC would be required to maintain a minimum fixed charge coverage ratio (as defined in the Revolving Credit Facility) for the trailing four quarters equal to at least 1.0 to 1.0; subject to CPG International LLC’s ability to make an equity cure (no more than twice in any four quarter period and up to five times over the life of the facility). As of March 31, 2022, CPG International LLC was in compliance with the financial and nonfinancial covenants imposed by the Revolving Credit Facility. The Revolving Credit Facility also includes customary events of default, including the occurrence of a change of control. Interest expense consisted of the following (in thousands): Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Interest Expense Term Loan Agreement $ 3,798 $ 4,423 $ 7,682 $ 10,100 Revolving Credit Facility 260 154 419 317 Other 818 204 1,684 408 Amortization - Debt issue costs Term Loan Agreement 254 1,698 508 1,989 Revolving Credit Facility 66 223 131 364 Term Loan OID 30 97 61 132 Capitalized interest (1,216 ) (451 ) (2,327 ) (936 ) Interest expense $ 4,010 $ 6,348 $ 8,158 $ 12,374 See Note 11 for the fair value of the Company’s debt as of March 31, 2022 and September 30, 2021.

Product Warranties

Product Warranties	6 Months Ended
	Mar. 31, 2022
Product Warranties Disclosures [Abstract]
Product Warranties	9. PRODUCT WARRANTIES The Company provides product assurance warranties of various lengths ranging from 5 years to lifetime for limited coverage for a variety of material and workmanship defects based on standard terms and conditions between the Company and its customers. Warranty coverage depends on the product involved. The warranty reserve activity consisted of the following (in thousands): Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Beginning balance $ 12,681 $ 11,044 $ 12,699 $ 10,913 Adjustments to reserve 1,810 1,827 2,277 2,550 Warranty claims payment (543 ) (817 ) (1,028 ) (1,426 ) Accretion - purchase accounting valuation — 11 — 28 Ending balance 13,948 12,065 13,948 12,065 Current portion of accrued warranty (3,218 ) (2,809 ) (3,218 ) (2,809 ) Accrued warranty – less current portion $ 10,730 $ 9,256 $ 10,730 $ 9,256

Leases

Leases	6 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Leases	10. LEASES As discussed in Note 1, on October 1, 2020, the Company adopted ASU No. 2016-02, Leases (Topic 842) For leases with initial terms greater than 12 months, the Company considers these right-of-use assets and records the related asset and obligation at the present value of lease payments over the term. For leases with initial terms equal to or less than 12 months, the Company does not consider them as right-of-use assets and instead considers them short-term lease costs that are recognized on a straight-line basis over the lease term. The Company’s leases may include escalation clauses, renewal options and/or termination options that are factored into the determination of lease term and lease payments when it is reasonably certain the option will be exercised. Renewal options range from 1 year to 20 years. Lease assets and lease liabilities as of March 31, 2022 and September 30, 2021 were as follows (in thousands): Leases Classification on Balance Sheet March 31, 2022 September 30, 2021 Assets ROU operating lease assets Other assets $ 21,180 $ 19,431 Finance lease assets Other assets 53,906 49,084 Total lease assets $ 75,086 $ 68,515 Liabilities Current Operating Accrued expenses and other liabilities $ 5,018 $ 3,906 Finance Accrued expenses and other liabilities 1,217 71 Non-Current Operating Other non-current liabilities 19,100 18,585 Finance Other non-current liabilities 55,996 50,590 Total lease liabilities $ 81,331 $ 73,152 The components of lease expense for the three and six months ended March 31, 2022 and 2021 were as follows: Three Months Ended March 31, Six Months Ended March 31, (in thousands) 2022 2021 2022 2021 Operating lease expense $ 1,454 $ 999 $ 2,624 $ 1,783 Finance lease amortization of assets 797 276 1,514 524 Finance lease interest on lease liabilities 868 203 1,673 406 Short term 171 28 218 53 Sublease income (87 ) (119 ) (206 ) (189 ) Total lease expense $ 3,203 $ 1,387 $ 5,823 $ 2,577 The tables below present supplemental information related to leases as of March 31, 2022 and September 30, 2021: Weighted-average remaining lease term (years) March 31, 2022 September 30, 2021 Operating leases 7.0 7.8 Finance leases 30.7 32.2 Weighted-average discount rate Operating leases 4.1 % 4.3 % Finance leases 6.3 % 6.5 % The following table summarizes the maturities of lease liabilities at March 31, 2022: (in thousands) Operating Leases Finance Leases Total 2022 $ 2,954 $ 2,248 $ 5,202 2023 5,763 4,661 10,424 2024 4,592 4,375 8,967 2025 3,503 4,166 7,669 2026 2,250 3,963 6,213 Thereafter 9,291 105,243 114,534 Total lease payments 28,353 124,656 153,009 Less: Interest (4,235 ) (67,443 ) (71,678 ) Present Value of lease liability $ 24,118 $ 57,213 $ 81,331

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	11. FAIR VALUE OF FINANCIAL INSTRUMENTS FASB Accounting Standards Codification (“ASC”) requirements for Fair Value Measurements and Disclosures establish a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three levels. Level 1 inputs, the highest priority, are quoted prices in active markets for identical assets or liabilities. Level 2 inputs reflect other than quoted prices included in Level 1 that are either observable directly or through corroboration with observable market data. Level 3 inputs are unobservable inputs, due to little or no market activity for the asset or liability, such as internally-developed valuation models. We do not have any assets or liabilities measured at fair value on a recurring basis that are Level 3. The carrying values and the estimated fair values of the debt financial instruments (Level 2 measurements) consisted of the following (in thousands): March 31, 2022 September 30, 2021 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Term Loan due May 5, 2024 $ 467,654 $ 463,071 $ 467,654 $ 467,420 Revolving Credit Facility, expires March 31, 2026 40,000 40,000 — — Financial instruments remeasure at fair value on a recurring basis –

Segments

Segments	6 Months Ended
	Mar. 31, 2022
Segment Reporting [Abstract]
Segments	12. SEGMENTS Operating segments for the Company are determined based on information used by the chief operating decision maker (“CODM”) in deciding how to evaluate performance and allocate resources to each of the segments. The CODM reviews Adjusted EBITDA and Adjusted EBITDA Margin as the key segment measures of performance. Adjusted EBITDA is defined as segment operating income (loss) plus depreciation and amortization, adjusted by adding thereto or subtracting therefrom stock-based compensation costs, business transformation costs, acquisition costs, capital structure transaction costs, and certain other costs. Adjusted EBITDA Margin is defined as Adjusted EBITDA divided by net sales. The Company has two reportable segments, Residential and Commercial. The reportable segments were determined primarily based on products and end markets as follows: • Residential—The Residential segment manufactures and distributes decking, rail, trim and accessories through a national network of dealers and distributors and multiple home improvement retailers providing extensive geographic coverage and enabling the Company to effectively serve contractors. The addition of StruXure expands our product offerings in the Residential segment. The addition of regional recyclers provides full-service recycled PVC material processing, sourcing, logistical support, and scrap management programs. This segment is impacted by trends in and the strength of home repair and remodel activity. • Commercial—The Commercial segment manufactures, fabricates and distributes resin based extruded sheeting products for a variety of commercial and industrial applications through a widespread distribution network as well as directly to original equipment manufacturers. This segment includes Scranton Products which manufactures lockers and partitions and Vycom which manufactures resin based sheeting products. This segment is impacted by trends in and the strength of the new construction sector. The segment data below includes data for Residential and Commercial for the three and six months ended March 31, 2022 and 2021 (in thousands). Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Net sales to customers Residential $ 350,358 $ 262,198 $ 571,491 $ 447,838 Commercial 45,897 30,923 84,472 57,561 Total $ 396,255 $ 293,121 $ 655,963 $ 505,399 Adjusted EBITDA Residential $ 98,350 $ 81,699 $ 167,781 $ 140,475 Commercial 8,675 3,714 13,423 7,030 Total Adjusted EBITDA for reporting segments $ 107,025 $ 85,413 $ 181,204 $ 147,505 Unallocated net expenses (16,104 ) (13,902 ) (31,763 ) (27,542 ) Adjustments to Income (loss) before income tax provision Depreciation and amortization (29,042 ) (25,271 ) (57,124 ) (49,549 ) Stock-based compensation costs (4,928 ) (7,156 ) (8,944 ) (10,136 ) Acquisition costs (1) (5,136 ) — (5,633 ) — Initial public offering costs and Secondary offering costs — (1,149 ) — (1,149 ) Other costs (2) (177 ) (1,390 ) (662 ) (3,053 ) Interest expense, net (4,010 ) (6,348 ) (8,158 ) (12,374 ) Income (loss) before income tax provision $ 47,628 $ 30,197 $ 68,920 $ 43,702 (1) Acquisition costs reflect costs directly related to completed acquisitions of $3.9 million and $4.4 million in the three and six months ended March 31, 2022, respectively, and inventory step-up adjustments related to recording inventory of acquired businesses at fair value on the date of acquisition of $1.2 million for both the three and six months ended March 31, 2022. ( 2 ) Other costs include costs for legal expense of $0.1 million and $0.5 million in the three months ended March 31, 2022 and 2021, respectively, costs related to an incentive plan and other ancillary expenses associated with the initial public offering of $0.7 million for the three months ended March 31, 2021, other costs of $0.1 million for the three months ended March 31, 2022, and the impact of retroactive adoption of ASC 842 of $0.2 million for the three months ended March 31, 2021. Other costs include costs for legal expense of $0.4 million and $1.0 million in the six months ended March 31, 2022 and 2021, respectively, costs related to an incentive plan and other ancillary expenses associated with the initial public offering of $0.1 million and $1.7 million in the six months ended March 31, 2022 and 2021, respectively, other costs of $0.2 million for the six months ended March 31, 2022, and the impact of retroactive adoption of ASC 842 of $0.4 million for the six months ended March 31, 2021.

Capital Stock

Capital Stock	6 Months Ended
	Mar. 31, 2022
Stockholders Equity Note [Abstract]
Capital Stock	13. CAPITAL STOCK The Company completed its IPO on June 16, 2020, in which it sold 38,237,500 shares of its Class A common stock, including 4,987,500 shares pursuant to the underwriters’ over-allotment option. The shares were sold at an IPO price of $23.00 per share for net proceeds to the Company of approximately $819.7 million, after deducting underwriting discounts and commissions of $50.6 million and offering expenses of approximately $9.2 million payable by the Company. Immediately prior to the completion of the IPO, the Company converted to a Delaware corporation from a limited liability company. The Company’s certificate of incorporation provides for two classes of common stock: Class A common stock and Class B common stock. In addition, the certificate of incorporation authorizes shares of undesignated preferred stock, the rights, preferences and privileges of which may be designated from time to time by the board of directors. The Company is authorized to issue up to 1.1 billion shares of Class A common stock, up to 1 hundred In conjunction with the Corporate Conversion and prior to the closing of the IPO, the Company effected a unit split of its then-outstanding unit, resulting in an aggregate of 108,162,741 units, including 75,093,778 Class A units and 33,068,963 Class B units. Concurrently with the Corporate Conversion, the units were converted to an aggregate of 108,162,741 shares of common stock, including 75,093,778 shares of Class A common stock and 33,068,963 shares of Class B common stock. In addition, a class of the Company’s former indirect parent’s partnership interests referred to as “Profits Interests” were exchanged for an aggregate of 2,703,243 shares of Class A common stock and 5,532,057 shares of Class A restricted stock, and 3,477,413 shares of Class A common stock reserved for issuance upon the exercise of stock options. On January 26, 2021, the Company completed an offering of 23,000,000 shares of Class A common stock, par value $0.001 per share, including the exercise in full by the underwriters of their option to purchase up to 3,000,000 additional shares of Class A common stock, at a public offering price of $40.00 per share. The shares were sold by certain of the Selling Stockholders. The Company did not receive any of the proceeds from the sale of the shares by those Selling Stockholders. In connection with the offering the Company incurred approximately $1.2 million in expenses. On June 1, 2021, the Company completed an offering of 17,250,000 shares of Class A common stock, par value $0.001 per share, including the exercise in full by the underwriters of their option to purchase up to 2,250,000 additional shares of Class A common stock, at a public offering price of $43.50 per share. The shares were sold by certain of the Selling Stockholders. The Company did not receive any of the proceeds from the sale of the shares by those Selling Stockholders. In connection with the offering the Company incurred approximately $1.1 million in expenses.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Mar. 31, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	14. STOCK-BASED COMPENSATION The Company grants stock-based awards to attract, retain and motivate key employees and directors. The 2020 Omnibus Incentive Compensation Plan (“2020 Plan”), provides for the grant of stock options, stock appreciation rights, restricted stock, restricted stock units, dividend equivalent rights, and performance-based or other equity-related awards to the Company’s employees and directors. The maximum aggregate number of shares that may be issued under the 2020 Plan is 15,852,319 shares with 3,849,011 shares remaining in the reserve. The total aggregate number of shares may be adjusted as determined by the Board of Directors. Stock-based compensation expense for the three months ended March 31, 2022 and 2021 was $4.9 million and $7.2 million, respectively and for the six months ended March 31, 2022 and 2021was $8.9 million and $10.1 million, respectively, recognized in “Selling, general and administrative expenses” in the Condensed Consolidated Statements of Comprehensive Income (Loss). Total income tax benefit for the three months ended March 31, 2022 and 2021 was $1.1 million and $0.3 million, respectively, and for the six months ended March 31, 2022 and 2021 was $1.9 million and $0.8 million. As of March 31, 2022, the Company had not yet recognized compensation cost on unvested stock-based awards of $35.6 million, with a weighted average remaining recognition period of 2.3 years. The Company uses the Monte Carlo pricing model to estimate the fair value of its performance-based awards as of the grant date, and uses the Black Scholes pricing model to estimate the fair value of its service-based awards as of the grant date. Under the terms of the 2020 Plan, all stock options will expire if not exercised within ten years of the grant date. The following table sets forth the significant assumptions used for the calculation of stock-based compensation expense for the six months ended March 31, 2022 and 2021: November 19, 2021 Grant Date December 4, 2020 Grant Date Risk-free interest rate 1.34 % 0.56 % Expected volatility 40.00 % 35.00 % Expected term (in years) 6.00 6.00 Expected dividend yield 0.00 % 0.00 % Stock Options The following table summarizes the performance-based stock option activity for the six months ended March 31, 2022: Number of Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contract Term Aggregate Intrinsic Value (in years) (in thousands) Outstanding at October 1, 2021 1,556,489 $ 23.00 Granted — — Exercised (123,008 ) 23.00 Cancelled/Forfeited (2 ) 23.00 Outstanding at March 31, 2022 1,433,479 23.00 8.2 2,638 Vested and exercisable at March 31, 2022 1,433,479 $ 23.00 8.2 2,638 The following table summarizes the service-based stock option activity for the six months ended March 31, 2022: Number of Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contract Term Aggregate Intrinsic Value (in years) (in thousands) Outstanding at October 1, 2021 3,434,221 $ 23.82 Granted 324,768 42.79 Exercised (91,033 ) 23.00 Cancelled/Forfeited (41,410 ) 24.74 Outstanding at March 31, 2022 3,626,546 25.53 8.3 5,675 Vested and exercisable at March 31, 2022 1,662,842 $ 23.24 8.0 2,993 Restricted Stock Awards A summary of the service-based restricted stock awards activity during the six months ended March 31, 2022 was as follows: Number of Shares Weighted Average Grant Date Fair Value Outstanding and unvested at October 1, 2021 717,580 $ 23.00 Granted — — Vested (245,308 ) 23.00 Forfeited (10,573 ) 23.00 Outstanding and unvested at March 31, 2022 461,699 $ 23.00 Performance Restricted Stock Units Performance restricted stock units were granted to officers and certain employees of the Company and represent the right to earn shares of Company common stock based on the achievement of company-wide non-GAAP performance conditions, including cumulative net sales, average return on net tangible assets and cumulative EBITDA during the three-year performance period. Compensation cost is amortized into expense over the performance period, which is generally three years, and is based on the probability of meeting performance targets. The fair value of each performance share award is based on the closing stock price on the date of grant. A summary of the performance-based restricted stock unit awards activity for the six months ended March 31, 2022 presented at target was as follows: Number of Shares Weighted Average Grant Date Fair Value Outstanding and unvested at October 1, 2021 111,804 $ 35.00 Granted 115,608 41.21 Vested — — Forfeited (6,295 ) 35.47 Outstanding and unvested at March 31, 2022 221,117 $ 38.23 Restricted Stock Units A summary of the service-based restricted stock unit awards activity for the six months ended March 31, 2022 was as follows: Number of Shares Weighted Average Grant Date Fair Value Outstanding and unvested at October 1, 2021 366,852 $ 30.42 Granted 224,900 37.85 Vested (51,154 ) 35.99 Forfeited (22,669 ) 30.82 Outstanding and unvested at March 31, 2022 517,929 $ 33.18

Earnings Per Share

Earnings Per Share	6 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Earnings Per Share	15. EARNINGS PER SHARE The Company computes earnings per common share (“EPS”) under the two-class method which requires the allocation of all distributed and undistributed earnings attributable to the Company to common stock and other participating securities based on their respective rights to receive distributions of earnings or losses. The Company’s Class A common stock and Class B common stock equally share in distributed and undistributed earnings, therefore, no allocation to participating securities or dilutive securities is performed. Basic EPS attributable to common stockholders is calculated by dividing net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock outstanding. Diluted EPS is calculated by adjusting weighted average shares outstanding for the dilutive effect of potential common shares, determined using the treasury-stock method. For purposes of the diluted EPS calculation, restricted stock awards, restricted stock units and options to purchase shares of common stock are considered to be potential common shares. The following table sets forth the computation of the Company’s basic and diluted EPS attributable to common stockholders (in thousands, except share and per share amounts): Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Numerator: Net income (loss) $ 35,818 $ 22,640 $ 52,525 $ 32,788 Net income (loss) attributable to common stockholders- basic and diluted $ 35,818 $ 22,640 $ 52,525 $ 32,788 Denominator: Weighted-average shares of common stock Basic 154,661,277 153,509,612 154,551,589 153,366,516 Diluted 156,121,476 156,747,514 156,560,502 156,377,902 Net income (loss) per share attributable to common stockholders: Net income (loss) per common share - basic $ 0.23 $ 0.15 $ 0.34 $ 0.21 Net income (loss) per common share - diluted $ 0.23 $ 0.14 $ 0.34 $ 0.21 The following table includes the number of shares that may be dilutive common shares in the future, and were not included in the computation of diluted net income (loss) per share because the effect was anti-dilutive: Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Stock Options 535,161 117,989 388,946 76,498 Restricted Stock Units 303,624 2,607 204,607 1,289

Income Taxes

Income Taxes	6 Months Ended
	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	16. INCOME TAXES The Company calculates the interim tax provision in accordance with the provisions of ASC 740-270, Income Taxes; Interim Reporting

Commitments And Contingencies

Commitments And Contingencies	6 Months Ended
	Mar. 31, 2022
Commitments And Contingencies Disclosure [Abstract]
Commitments And Contingencies	17. COMMITMENTS AND CONTINGENCIES Legal Proceedings During the year ended September 30, 2019, the Company was made aware of a worker’s compensation case that became reasonably possible to give rise to a liability. The case is in discovery as the nature and extent of the Company’s exposure is currently being determined. The Company expects a range of loss of $0.4 million to $0.5 million. In the normal course of the Company’s business, it is at times subject to various other legal actions, in some cases for which the relief or damages sought may be substantial. Although the Company is not able to predict the outcome of such actions, after reviewing all pending and threatened actions with counsel and based on information currently available, management believes that the outcome of such actions, individually or in the aggregate, will not have a material adverse effect on the Company’s results of operations or financial position. However, it is possible that the ultimate resolution of such matters, if unfavorable, may be material to the Company’s results of operations in a particular future period as the time and amount of any resolution of such actions and its relationship to the future results of operations are not currently known. The Company accrues for losses when they are probable of occurrence and such losses are reasonably estimable. Legal costs expected to be incurred are accounted for as they are incurred.

Condensed Financial Information

Condensed Financial Information of Registrant (Parent Company Only)	6 Months Ended
	Mar. 31, 2022
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Condensed Financial Information of Registrant (Parent Company Only)	18. CONDENSED FINANCIAL INFORMATION OF REGISTRANT (PARENT COMPANY ONLY) The AZEK Company Inc. (parent company only) Balance Sheets (In thousands of U.S. dollars, except for share and per share amounts) March 31, 2022 September 30, 2021 ASSETS: Non-current assets: Investments in subsidiaries $ 1,493,034 $ 1,427,164 Total non-current assets 1,493,034 1,427,164 Total assets $ 1,493,034 $ 1,427,164 LIABILITIES AND STOCKHOLDERS’ EQUITY: Total liabilities $ — Stockholders’ equity: Preferred stock, $0.001 par value; 1,000,000 shares authorized and no shares issued and outstanding at March 31, 2022 and at September 30, 2021, respectively — — Class A common stock, $0.001 par value; 1,100,000,000 shares authorized, 155,108,627 shares issued and outstanding at March 31, 2022 and 154,866,313 shares issued and outstanding at September 30, 2021 155 155 Class B common stock, $0.001 par value; 100,000,000 shares authorized, 100 shares issued and outstanding at March 31, 2022 and at September 30, 2021, respectively — — Additional paid-in capital 1,628,581 1,615,236 Accumulated deficit (135,702 ) (188,227 ) Total stockholders’ equity 1,493,034 1,427,164 Total liabilities and stockholders’ equity $ 1,493,034 $ 1,427,164 Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Net income (loss) of subsidiaries $ 35,818 $ 22,640 $ 52,525 $ 32,788 Net income (loss) of subsidiaries $ 35,818 $ 22,640 $ 52,525 $ 32,788 Comprehensive income (loss) $ 35,818 $ 22,640 $ 52,525 $ 32,788 The AZEK Company Inc. did not have any cash as of March 31, 2022 or September 30, 2021, accordingly a Condensed Statement of Cash Flows has not been presented. Basis of Presentation The parent company financial statements should be read in conjunction with the Company’s Consolidated Financial Statements and the accompanying notes thereto. For purposes of this condensed financial information, the Company’s wholly owned and majority owned subsidiaries are recorded based upon its proportionate share of the subsidiaries’ net assets (similar to presenting them on the equity method). Since the restricted net assets of The AZEK Company Inc. and its subsidiaries exceed 25% of the consolidated net assets of the Company and its subsidiaries, the accompanying condensed parent company financial statements have been prepared in accordance with Rule 12-04, Schedule 1 of Regulation S-X. This information should be read in conjunction with the accompanying Condensed Consolidated Financial Statements. Dividends from Subsidiaries There were no cash dividends paid to The AZEK Company Inc. from the Company’s consolidated subsidiaries during each of the three and six months ended March 31, 2022 and 2021. Restricted Payments CPG International LLC is party to the Revolving Credit Facility and the Term Loan Agreement originally executed on September 30, 2013, both of which have been amended and extended from time to time. The obligations under the Revolving Credit Facility and Term Loan Agreement are secured by substantially all of the present and future assets of the borrowers and guarantors, including equity interests of their domestic subsidiaries, subject to certain exceptions. The obligations under the Revolving Credit Facility and Term Loan Agreement are guaranteed by the Company and its wholly owned domestic subsidiaries other than certain immaterial subsidiaries and other excluded subsidiaries. CPG International LLC is not permitted to make certain payments unless those payments are consistent with exceptions outlined in the agreements. These payments include repurchase of equity interests, fees associated with a public offering, income taxes due in other applicable payments. Further, the payments are only permitted if certain conditions are met related to availability and fixed charge coverage as defined in the Revolving Credit Facility and described in Note 8 “Debt” to these Condensed Consolidated Financial Statements.

Subsequent Events

Subsequent Events	6 Months Ended
	Mar. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	19. SUBSEQUENT EVENTS On April 28, 2022, the Company entered into a new $600 million first lien term loan credit facility pursuant to the 2022 Term Loan Agreement, the proceeds of which were applied, among other uses, to prepay the obligations of the Term Loan Agreement in full. The 2022 Term Loan Agreement will mature on April 28, 2029 and the loans thereunder bear an interest rate equal to (i) in the case of ABR borrowings, the highest of (a) the Federal Funds Rate plus 0.50%, (b) the Prime Rate as in effect on such day and (c) the one-month Term SOFR rate plus 1.00% per annum, provided that in no event will the alternative base rate be less than 1.50% per annum, plus an applicable margin of 1.50% and (ii) in the case of SOFR borrowings, the Term SOFR rate for the applicable interest period, in each case, plus an applicable margin of 2.50%. The 2022 Term Loan Agreement contains customary affirmative and negative covenants for credit facilities of this type. On May 5, 2022, the Board of Directors authorized the Company to repurchase up to $400 million of the Company’s Class A common stock. The program allows the Company to repurchase its shares opportunistically from time to time. Purchases may be effected through one or more open market transactions, privately negotiated transactions, transactions structured through investment banking institutions, accelerated share repurchases or tender offers, some of which may be effected through Rule 10b5-1 plans, or a combination of the foregoing. The timing of repurchases will depend upon several factors, including market and business conditions, and repurchases may be discontinued at any time.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company operates on a fiscal year ending September 30. The accompanying unaudited Condensed Consolidated Financial Statements and notes have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information, and in management’s opinion, includes all adjustments, consisting of only normal recurring adjustments, necessary for the fair statement of the Company’s financial position, its results of operations and cash flows for the interim periods presented. The results of operations for the three and six months ended March 31, 2022 and the cash flows for the six months ended March 31, 2022 are not necessarily indicative of the results to be expected for the full fiscal year or any other period. The Company’s financial condition and results of operations are being, and are expected to continue to be affected by the current COVID-19 public health pandemic. The economic effects of the COVID-19 pandemic will likely continue to affect demand for the Company’s products in the foreseeable future. Although management has implemented measures to mitigate any impact of the COVID-19 pandemic on the Company’s business, financial condition and results of operations, these measures may not fully mitigate the impact of the COVID-19 pandemic on the Company’s business, financial condition and results of operations. Management cannot predict the degree to, or the period over, which the Company will be affected by the COVID-19 pandemic and resulting governmental and other measures. The accompanying unaudited Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and notes thereto included in the Company’s 2021 Form 10-K. The Condensed Consolidated Balance Sheet as of September 30, 2021 was derived from the audited financial statements at that date. There have been no material changes in the Company’s significant accounting policies from those that were disclosed in the 2021 Form 10-K, except as noted below.
Revision of Previously Reported Financial Information	Revision of Previously Reported Financial Information In connection with our retroactive adoption of ASC 842 as of October 1, 2020, quarterly amounts presented in our prior Form 10-Q were revised. The impact of the adjustments was immaterial to the Consolidated Financial Statements.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Significant estimates include revenue recognition, reserves for excess inventory, inventory obsolescence, product warranties, customer rebates, stock-based compensation, litigation, income taxes, contingent consideration, goodwill and intangible asset valuation and accounting for long-lived assets. Management’s estimates and assumptions are evaluated on an ongoing basis and are based on historical experience, current conditions and available information. Actual results may differ from estimated amounts. Estimates are revised as additional information becomes available.
Accounting Policies	Accounting Policies Refer to the Company’s 2021 Form 10-K for a discussion of the Company’s accounting policies, as updated below and for recently adopted accounting standards.
Research and Development Costs	Research and Development Costs Research and development costs primarily relate to new product development, product claims support and manufacturing process improvements. Such costs are expensed as incurred and are included in “Selling, general and administrative expenses” within the Condensed Consolidated Statements of Comprehensive Income (Loss). Total research and development expenses were $2.3 million and $1.7 million, respectively, for the three months ended March 31, 2022 and 2021, and $4.3 million and $3.6 million, respectively, for the six months ended March 31, 2022 and 2021.
Recently Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements On October 1, 2020, the Company adopted ASU No. 2016-02, Leases (Topic 842) On October 1, 2021, the Company adopted ASU No. 2019-12, Income Taxes (Topic 740)—Simplifying the Accounting for Income Taxes

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Mar. 31, 2022
Revenue From Contract With Customer [Abstract]
Summary of Rebate Activity	The rebate activity was as follows (in thousands): Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Beginning balance $ 53,841 $ 38,819 $ 47,648 $ 32,679 Rebate expense 30,402 20,539 46,552 34,212 Rebate payments (44,097 ) (31,567 ) (54,054 ) (39,100 ) Ending balance $ 40,146 $ 27,791 $ 40,146 $ 27,791

Business Combinations (Tables)

Business Combinations (Tables)	6 Months Ended
	Mar. 31, 2022
Business Combinations [Abstract]
Summary of Preliminary Allocation of Assets Acquired and Liabilities Assumed	The following table represents the preliminary allocation of assets acquired and liabilities assumed on the acquisition date for both acquisitions as of March 31, 2022 (in thousands): (US dollars in thousands) Total Cash and cash equivalents $ 1,410 Trade receivables 3,798 Inventories 11,655 Other current assets 95 Property and equipment 4,618 Intangible assets 43,000 Accounts payable (3,110 ) Accrued expenses and other liabilities (9,171 ) Total identifiable assets 52,295 Goodwill 36,050 Net assets acquired/total consideration 88,345 Less: cash acquired (1,410 ) Total consideration net of cash acquired $ 86,935

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Mar. 31, 2022
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consisted of the following (in thousands): in thousands March 31, 2022 September 30, 2021 Raw materials $ 74,120 $ 46,046 Work in process 37,826 27,278 Finished goods 187,214 115,564 Total inventories $ 299,160 $ 188,888

Property, Plant and Equipment_2

Property, Plant and Equipment - Net (Tables)	6 Months Ended
	Mar. 31, 2022
Property Plant And Equipment [Abstract]
Summary of Property, Plant and Equipment - Net	Property, plant and equipment – net consisted of the following (in thousands): March 31, 2022 September 30, 2021 Land and improvements $ 3,222 $ 2,812 Buildings and improvements 80,397 73,227 Manufacturing equipment 462,924 405,611 Computer equipment 24,866 23,915 Furniture and fixtures 7,124 6,018 Vehicles 830 604 Total property and equipment 579,363 512,187 Construction in progress 173,929 129,886 753,292 642,073 Accumulated depreciation (278,952 ) (251,061 ) Total property and equipment – net $ 474,340 $ 391,012

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Net (Tables)	6 Months Ended
	Mar. 31, 2022
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Changes in Carrying Amount of Goodwill	Goodwill consisted of the following (in thousands): Residential Commercial Total Goodwill as of September 30, 2021 $ 911,001 $ 40,389 $ 951,390 Acquisitions 36,050 — 36,050 Goodwill as of March 31, 2022 $ 947,051 $ 40,389 $ 987,440 Accumulated impairment losses as of September 30, 2021 — 32,200 32,200 Accumulated impairment losses as of March 31, 2022 $ — $ 32,200 $ 32,200
Summary of Finite-lived Intangible Assets	Finite-lived intangible assets consisted of the following (in thousands): March 31, 2022 Lives in Years Gross Carrying Value Accumulated Amortization Net Carrying Value Proprietary knowledge 10 - 15 $ 299,300 $ (225,969 ) $ 73,331 Trademarks 5 - 20 229,340 (143,911 ) 85,429 Customer relationships 15 - 19 169,552 (70,800 ) 98,752 Patents 10 7,000 (4,518 ) 2,482 Other intangibles 3 - 15 4,076 (3,942 ) 134 Total intangible assets $ 709,268 $ (449,140 ) $ 260,128 September 30, 2021 Lives in Years Gross Carrying Value Accumulated Amortization Net Carrying Value Propriety knowledge 10 — 15 $ 289,300 $ (216,283 ) $ 73,017 Trademarks 5 — 20 223,840 (139,631 ) 84,209 Customer relationships 15 — 19 146,670 (64,412 ) 82,258 Patents 10 7,000 (4,105 ) 2,895 Other intangible assets 3 — 15 4,076 (3,883 ) 193 Total intangible assets $ 670,886 $ (428,314 ) $ 242,572

Composition of Certain Balanc_2

Composition of Certain Balance Sheet Accounts (Tables)	6 Months Ended
	Mar. 31, 2022
Composition Of Certain Balance Sheet Accounts Disclosure [Abstract]
Summary of Allowance for Doubtful Accounts	Allowance for doubtful accounts consisted of the following (in thousands): Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Beginning balance $ 1,074 $ 1,338 $ 1,109 $ 1,332 Provision 98 149 63 155 Bad debt write-offs — — — — Ending balance $ 1,172 $ 1,487 $ 1,172 $ 1,487
Schedule of Accrued Expenses and Other Liabilities	Accrued expenses consisted of the following (in thousands): March 31, 2022 September 30, 2021 Employee related liabilities $ 24,590 $ 32,996 Customer deposits 10,676 — Lease liability - operating 5,018 3,906 Marketing 3,847 3,421 Warranty 3,218 2,992 Construction in progress 8,421 4,068 Professional fees 1,737 2,296 Freight 2,211 2,292 Lease liability - finance 1,217 71 Other 4,651 4,480 Total accrued expenses and other current liabilities $ 65,586 $ 56,522

Debt (Tables)

Debt (Tables)	6 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Summary of Long-term Debt	Debt consisted of the following (in thousands): March 31, 2022 September 30, 2021 Term Loan due May 5, 2024 — LIBOR + 2.50% (3.25% at both March 31, 2022 and September 30, 2021) $ 467,654 $ 467,654 Revolving Credit Facility through March 31, 2026 - LIBOR + 1.25% (2.25% at March 31, 2022) 40,000 — Total 507,654 467,654 Less unamortized deferred financing costs (2,117 ) (2,625 ) Less unamortized original issue discount (253 ) (314 ) Less current portion — Long-term debt—less current portion and unamortized deferred financing costs $ 505,284 $ 464,715
Summary of Interest Expense	Interest expense consisted of the following (in thousands): Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Interest Expense Term Loan Agreement $ 3,798 $ 4,423 $ 7,682 $ 10,100 Revolving Credit Facility 260 154 419 317 Other 818 204 1,684 408 Amortization - Debt issue costs Term Loan Agreement 254 1,698 508 1,989 Revolving Credit Facility 66 223 131 364 Term Loan OID 30 97 61 132 Capitalized interest (1,216 ) (451 ) (2,327 ) (936 ) Interest expense $ 4,010 $ 6,348 $ 8,158 $ 12,374

Product Warranties (Tables)

Product Warranties (Tables)	6 Months Ended
	Mar. 31, 2022
Product Warranties Disclosures [Abstract]
Summary of Warranty Reserve Activity	Warranty coverage depends on the product involved. The warranty reserve activity consisted of the following (in thousands): Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Beginning balance $ 12,681 $ 11,044 $ 12,699 $ 10,913 Adjustments to reserve 1,810 1,827 2,277 2,550 Warranty claims payment (543 ) (817 ) (1,028 ) (1,426 ) Accretion - purchase accounting valuation — 11 — 28 Ending balance 13,948 12,065 13,948 12,065 Current portion of accrued warranty (3,218 ) (2,809 ) (3,218 ) (2,809 ) Accrued warranty – less current portion $ 10,730 $ 9,256 $ 10,730 $ 9,256

Leases (Tables)

Leases (Tables)	6 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Summary of Lease Assets and Lease Liabilities	Lease assets and lease liabilities as of March 31, 2022 and September 30, 2021 were as follows (in thousands): Leases Classification on Balance Sheet March 31, 2022 September 30, 2021 Assets ROU operating lease assets Other assets $ 21,180 $ 19,431 Finance lease assets Other assets 53,906 49,084 Total lease assets $ 75,086 $ 68,515 Liabilities Current Operating Accrued expenses and other liabilities $ 5,018 $ 3,906 Finance Accrued expenses and other liabilities 1,217 71 Non-Current Operating Other non-current liabilities 19,100 18,585 Finance Other non-current liabilities 55,996 50,590 Total lease liabilities $ 81,331 $ 73,152
Components of Lease Expense	The components of lease expense for the three and six months ended March 31, 2022 and 2021 were as follows: Three Months Ended March 31, Six Months Ended March 31, (in thousands) 2022 2021 2022 2021 Operating lease expense $ 1,454 $ 999 $ 2,624 $ 1,783 Finance lease amortization of assets 797 276 1,514 524 Finance lease interest on lease liabilities 868 203 1,673 406 Short term 171 28 218 53 Sublease income (87 ) (119 ) (206 ) (189 ) Total lease expense $ 3,203 $ 1,387 $ 5,823 $ 2,577
Supplemental Information Related to Leases	The tables below present supplemental information related to leases as of March 31, 2022 and September 30, 2021: Weighted-average remaining lease term (years) March 31, 2022 September 30, 2021 Operating leases 7.0 7.8 Finance leases 30.7 32.2 Weighted-average discount rate Operating leases 4.1 % 4.3 % Finance leases 6.3 % 6.5 %
Summary of Maturities of Lease Liabilities	The following table summarizes the maturities of lease liabilities at March 31, 2022: (in thousands) Operating Leases Finance Leases Total 2022 $ 2,954 $ 2,248 $ 5,202 2023 5,763 4,661 10,424 2024 4,592 4,375 8,967 2025 3,503 4,166 7,669 2026 2,250 3,963 6,213 Thereafter 9,291 105,243 114,534 Total lease payments 28,353 124,656 153,009 Less: Interest (4,235 ) (67,443 ) (71,678 ) Present Value of lease liability $ 24,118 $ 57,213 $ 81,331

Fair Value Of Financial Instr_2

Fair Value Of Financial Instruments (Tables)	6 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Summary of Carrying Values and the Estimated Fair Values of the Debt Financial Instruments	The carrying values and the estimated fair values of the debt financial instruments (Level 2 measurements) consisted of the following (in thousands): March 31, 2022 September 30, 2021 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Term Loan due May 5, 2024 $ 467,654 $ 463,071 $ 467,654 $ 467,420 Revolving Credit Facility, expires March 31, 2026 40,000 40,000 — —

Segments (Tables)

Segments (Tables)	6 Months Ended
	Mar. 31, 2022
Segment Reporting [Abstract]
Summary of Residential and Commercial Segment Reporting Information	The segment data below includes data for Residential and Commercial for the three and six months ended March 31, 2022 and 2021 (in thousands). Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Net sales to customers Residential $ 350,358 $ 262,198 $ 571,491 $ 447,838 Commercial 45,897 30,923 84,472 57,561 Total $ 396,255 $ 293,121 $ 655,963 $ 505,399 Adjusted EBITDA Residential $ 98,350 $ 81,699 $ 167,781 $ 140,475 Commercial 8,675 3,714 13,423 7,030 Total Adjusted EBITDA for reporting segments $ 107,025 $ 85,413 $ 181,204 $ 147,505 Unallocated net expenses (16,104 ) (13,902 ) (31,763 ) (27,542 ) Adjustments to Income (loss) before income tax provision Depreciation and amortization (29,042 ) (25,271 ) (57,124 ) (49,549 ) Stock-based compensation costs (4,928 ) (7,156 ) (8,944 ) (10,136 ) Acquisition costs (1) (5,136 ) — (5,633 ) — Initial public offering costs and Secondary offering costs — (1,149 ) — (1,149 ) Other costs (2) (177 ) (1,390 ) (662 ) (3,053 ) Interest expense, net (4,010 ) (6,348 ) (8,158 ) (12,374 ) Income (loss) before income tax provision $ 47,628 $ 30,197 $ 68,920 $ 43,702 (1) Acquisition costs reflect costs directly related to completed acquisitions of $3.9 million and $4.4 million in the three and six months ended March 31, 2022, respectively, and inventory step-up adjustments related to recording inventory of acquired businesses at fair value on the date of acquisition of $1.2 million for both the three and six months ended March 31, 2022. ( 2 ) Other costs include costs for legal expense of $0.1 million and $0.5 million in the three months ended March 31, 2022 and 2021, respectively, costs related to an incentive plan and other ancillary expenses associated with the initial public offering of $0.7 million for the three months ended March 31, 2021, other costs of $0.1 million for the three months ended March 31, 2022, and the impact of retroactive adoption of ASC 842 of $0.2 million for the three months ended March 31, 2021. Other costs include costs for legal expense of $0.4 million and $1.0 million in the six months ended March 31, 2022 and 2021, respectively, costs related to an incentive plan and other ancillary expenses associated with the initial public offering of $0.1 million and $1.7 million in the six months ended March 31, 2022 and 2021, respectively, other costs of $0.2 million for the six months ended March 31, 2022, and the impact of retroactive adoption of ASC 842 of $0.4 million for the six months ended March 31, 2021.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Mar. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Share-Based Payment Award Valuation Assumptions	The following table sets forth the significant assumptions used for the calculation of stock-based compensation expense for the six months ended March 31, 2022 and 2021: November 19, 2021 Grant Date December 4, 2020 Grant Date Risk-free interest rate 1.34 % 0.56 % Expected volatility 40.00 % 35.00 % Expected term (in years) 6.00 6.00 Expected dividend yield 0.00 % 0.00 %
Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Share-Based Compensation Stock Options Activity	The following table summarizes the performance-based stock option activity for the six months ended March 31, 2022: Number of Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contract Term Aggregate Intrinsic Value (in years) (in thousands) Outstanding at October 1, 2021 1,556,489 $ 23.00 Granted — — Exercised (123,008 ) 23.00 Cancelled/Forfeited (2 ) 23.00 Outstanding at March 31, 2022 1,433,479 23.00 8.2 2,638 Vested and exercisable at March 31, 2022 1,433,479 $ 23.00 8.2 2,638
Service Based Stock Option Activity [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Share-Based Compensation Stock Options Activity	The following table summarizes the service-based stock option activity for the six months ended March 31, 2022: Number of Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contract Term Aggregate Intrinsic Value (in years) (in thousands) Outstanding at October 1, 2021 3,434,221 $ 23.82 Granted 324,768 42.79 Exercised (91,033 ) 23.00 Cancelled/Forfeited (41,410 ) 24.74 Outstanding at March 31, 2022 3,626,546 25.53 8.3 5,675 Vested and exercisable at March 31, 2022 1,662,842 $ 23.24 8.0 2,993
Service Based Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Non-Vested Restricted Stock Activity	A summary of the service-based restricted stock awards activity during the six months ended March 31, 2022 was as follows: Number of Shares Weighted Average Grant Date Fair Value Outstanding and unvested at October 1, 2021 717,580 $ 23.00 Granted — — Vested (245,308 ) 23.00 Forfeited (10,573 ) 23.00 Outstanding and unvested at March 31, 2022 461,699 $ 23.00
Schedule of Unvested Restricted Stock Units	A summary of the service-based restricted stock unit awards activity for the six months ended March 31, 2022 was as follows: Number of Shares Weighted Average Grant Date Fair Value Outstanding and unvested at October 1, 2021 366,852 $ 30.42 Granted 224,900 37.85 Vested (51,154 ) 35.99 Forfeited (22,669 ) 30.82 Outstanding and unvested at March 31, 2022 517,929 $ 33.18
Performance Based Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Non-Vested Restricted Stock Activity	A summary of the performance-based restricted stock unit awards activity for the six months ended March 31, 2022 presented at target was as follows: Number of Shares Weighted Average Grant Date Fair Value Outstanding and unvested at October 1, 2021 111,804 $ 35.00 Granted 115,608 41.21 Vested — — Forfeited (6,295 ) 35.47 Outstanding and unvested at March 31, 2022 221,117 $ 38.23

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Summary of Computation of Basic And Diluted Earnings Per Share	The following table sets forth the computation of the Company’s basic and diluted EPS attributable to common stockholders (in thousands, except share and per share amounts): Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Numerator: Net income (loss) $ 35,818 $ 22,640 $ 52,525 $ 32,788 Net income (loss) attributable to common stockholders- basic and diluted $ 35,818 $ 22,640 $ 52,525 $ 32,788 Denominator: Weighted-average shares of common stock Basic 154,661,277 153,509,612 154,551,589 153,366,516 Diluted 156,121,476 156,747,514 156,560,502 156,377,902 Net income (loss) per share attributable to common stockholders: Net income (loss) per common share - basic $ 0.23 $ 0.15 $ 0.34 $ 0.21 Net income (loss) per common share - diluted $ 0.23 $ 0.14 $ 0.34 $ 0.21
Summary of Antidilutive Securities Excluded From Computation of Earnings Per Share	The following table includes the number of shares that may be dilutive common shares in the future, and were not included in the computation of diluted net income (loss) per share because the effect was anti-dilutive: Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Stock Options 535,161 117,989 388,946 76,498 Restricted Stock Units 303,624 2,607 204,607 1,289

Condensed Financial Informati_2

Condensed Financial Information of Registrant (Parent Company Only) (Tables) - Parent Company [Member]	6 Months Ended
	Mar. 31, 2022
Schedule of Balance Sheets	The AZEK Company Inc. (parent company only) Balance Sheets (In thousands of U.S. dollars, except for share and per share amounts) March 31, 2022 September 30, 2021 ASSETS: Non-current assets: Investments in subsidiaries $ 1,493,034 $ 1,427,164 Total non-current assets 1,493,034 1,427,164 Total assets $ 1,493,034 $ 1,427,164 LIABILITIES AND STOCKHOLDERS’ EQUITY: Total liabilities $ — Stockholders’ equity: Preferred stock, $0.001 par value; 1,000,000 shares authorized and no shares issued and outstanding at March 31, 2022 and at September 30, 2021, respectively — — Class A common stock, $0.001 par value; 1,100,000,000 shares authorized, 155,108,627 shares issued and outstanding at March 31, 2022 and 154,866,313 shares issued and outstanding at September 30, 2021 155 155 Class B common stock, $0.001 par value; 100,000,000 shares authorized, 100 shares issued and outstanding at March 31, 2022 and at September 30, 2021, respectively — — Additional paid-in capital 1,628,581 1,615,236 Accumulated deficit (135,702 ) (188,227 ) Total stockholders’ equity 1,493,034 1,427,164 Total liabilities and stockholders’ equity $ 1,493,034 $ 1,427,164
Schedule of Statements of Comprehensive Income (Loss)	Three Months Ended March 31, Six Months Ended March 31, 2022 2021 2022 2021 Net income (loss) of subsidiaries $ 35,818 $ 22,640 $ 52,525 $ 32,788 Net income (loss) of subsidiaries $ 35,818 $ 22,640 $ 52,525 $ 32,788 Comprehensive income (loss) $ 35,818 $ 22,640 $ 52,525 $ 32,788

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jun. 01, 2021	Jan. 26, 2021	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2021	Oct. 01, 2020
Organization And Summary Of Significant Accounting Policies [Line Items]
Research and development expenses			$ 2,300	$ 1,700	$ 4,300	$ 3,600
Lease assets			75,086		75,086		$ 68,515	$ 15,200
Lease liabilities			81,331		81,331		73,152	18,700
Accumulated deficit			$ (135,702)		$ (135,702)		$ (188,227)
Revision of Prior Period Adjustment [Member] | Adoption of ASU [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit								$ 2,100
Common Class A [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Common stock, par value per share			$ 0.001		$ 0.001		$ 0.001
Common Class A [Member] | Secondary Offerings Member [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Stock shares sold by shareholders during the period	17,250,000	23,000,000
Common stock, par value per share	$ 0.001	$ 0.001
Estimated offering expenses	$ 1,100	$ 1,200
Common Class A [Member] | Over-Allotment Option [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Overallotment stock shares sold by shareholders during the period	2,250,000	3,000,000
Shares issued price	$ 43.50	$ 40
Common Class B [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Common stock, par value per share			$ 0.001		$ 0.001		$ 0.001

Revenue - Additional Informatio

Revenue - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021	Mar. 31, 2021
Revenue From Contract With Customer [Abstract]
Accrued rebates	$ 31,723	$ 44,339	$ 22,900
Contra trade receivable	$ 8,400		$ 4,900

Revenue - Summary of Rebate Act

Revenue - Summary of Rebate Activity (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Revenue From Contract With Customer [Abstract]
Beginning balance	$ 53,841	$ 38,819	$ 47,648	$ 32,679
Rebate expense	30,402	20,539	46,552	34,212
Rebate payments	(44,097)	(31,567)	(54,054)	(39,100)
Ending balance	$ 40,146	$ 27,791	$ 40,146	$ 27,791

Business Combinations - Additio

Business Combinations - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 29, 2021	Nov. 30, 2021	Mar. 31, 2022	Sep. 30, 2021
Business Acquisition [Line Items]
Business combination, recognized identifiable assets acquired and liabilities assumed intangible assets including goodwill			$ 79,100
Goodwill			987,440	$ 951,390
Goodwill, expected tax deductible amount			$ 36,100
Acquired finite lived intangible assets weighted average useful life			14 years 2 months 12 days
Customer Relationships [Member]
Business Acquisition [Line Items]
Business combination, recognized identifiable assets acquired and liabilities assumed intangible assets other than goodwill			$ 23,000
Acquired finite lived intangible asset useful life			15 years
Proprietary Knowledge [Member]
Business Acquisition [Line Items]
Business combination, recognized identifiable assets acquired and liabilities assumed intangible assets other than goodwill			$ 10,000
Acquired finite lived intangible asset useful life			10 years
Trademarks [Member]
Business Acquisition [Line Items]
Business combination, recognized identifiable assets acquired and liabilities assumed intangible assets other than goodwill			$ 10,000
Goodwill			$ 36,100
Acquired finite lived intangible asset useful life			15 years
Regional Recycler Midwest [Member]
Business Acquisition [Line Items]
Percentage of voting interest acquired		100.00%
Date of acquisition		Nov. 30, 2021
Purchase price		$ 4,200
StruXure Outdoor [Member]
Business Acquisition [Line Items]
Percentage of voting interest acquired	100.00%
Date of acquisition	Dec. 29, 2021
Purchase price	$ 84,100

Business Combinations - Summary

Business Combinations - Summary of Preliminary Allocation of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Mar. 31, 2022	Sep. 30, 2021
Business Acquisition [Line Items]
Goodwill		$ 987,440	$ 951,390
Frymans Recycling and StruXure Outdoor [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		1,410
Trade receivables		3,798
Inventories		11,655
Other current assets		95
Property and equipment		4,618
Intangible assets		43,000
Accounts payable		(3,110)
Accrued expenses and other liabilities		(9,171)
Total identifiable assets		52,295
Goodwill		36,050
Net assets acquired/total consideration		$ 88,345
Less: cash acquired	$ (1,410)
Total consideration net of cash acquired	$ 86,935

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Inventory Disclosure [Abstract]
Raw materials	$ 74,120	$ 46,046
Work in process	37,826	27,278
Finished goods	187,214	115,564
Total inventories	$ 299,160	$ 188,888

Property, Plant and Equipment_3

Property, Plant and Equipment - Net - Summary of Property, Plant and Equipment - Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Property Plant And Equipment [Line Items]
Land and improvements	$ 3,222	$ 2,812
Buildings and improvements	80,397	73,227
Manufacturing equipment	462,924	405,611
Furniture and fixtures	7,124	6,018
Property and Equipment Excluding Construction in Progress Gross	579,363	512,187
Construction in progress	173,929	129,886
Property and Equipment, Gross	753,292	642,073
Accumulated depreciation	(278,952)	(251,061)
Total property and equipment – net	474,340	391,012
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Property and Equipment Excluding Construction in Progress Gross	24,866	23,915
Vehicles [Member]
Property Plant And Equipment [Line Items]
Property and Equipment Excluding Construction in Progress Gross	$ 830	$ 604

Property, Plant and Equipment_4

Property, Plant and Equipment - Net - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Property Plant And Equipment [Abstract]
Depreciation	$ 16.5	$ 12.7	$ 31.7	$ 24.4
Interest Capitalized	$ 1.2	$ 0.5	$ 2.3	$ 0.9

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Net - Summary of Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2022	Sep. 30, 2021
Goodwill [Line Items]
Goodwill, beginning balance	$ 951,390
Acquisitions	36,050
Goodwill, ending balance	987,440
Accumulated impairment losses	32,200	$ 32,200
Residential [Member]
Goodwill [Line Items]
Goodwill, beginning balance	911,001
Acquisitions	36,050
Goodwill, ending balance	947,051
Commercial [Member]
Goodwill [Line Items]
Goodwill, beginning balance	40,389
Acquisitions	0
Goodwill, ending balance	40,389
Accumulated impairment losses	$ 32,200	$ 32,200

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Net - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Indefinite lived intangible assets other than goodwill	$ 0		$ 0		$ 0
Amortization expense	$ 12,600,000	$ 12,500,000	$ 25,444,000	$ 25,183,000
Remaining weighted-average amortization period for acquired intangible assets			12 years 3 months 18 days

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Net - Summary of Finite-Lived Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 31, 2022	Sep. 30, 2021
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 709,268	$ 670,886
Accumulated Amortization	(449,140)	(428,314)
Net Carrying Value	$ 260,128	242,572
Proprietary Knowledge [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	10 years
Gross Carrying Value	$ 299,300	289,300
Accumulated Amortization	(225,969)	(216,283)
Net Carrying Value	$ 73,331	73,017
Trademarks [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	15 years
Gross Carrying Value	$ 229,340	223,840
Accumulated Amortization	(143,911)	(139,631)
Net Carrying Value	$ 85,429	84,209
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	15 years
Gross Carrying Value	$ 169,552	146,670
Accumulated Amortization	(70,800)	(64,412)
Net Carrying Value	$ 98,752	$ 82,258
Patents [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	10 years	10 years
Gross Carrying Value	$ 7,000	$ 7,000
Accumulated Amortization	(4,518)	(4,105)
Net Carrying Value	2,482	2,895
Other intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	4,076	4,076
Accumulated Amortization	(3,942)	(3,883)
Net Carrying Value	$ 134	$ 193
Minimum [Member] | Proprietary Knowledge [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	10 years	10 years
Minimum [Member] | Trademarks [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	5 years	5 years
Minimum [Member] | Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	15 years	15 years
Minimum [Member] | Other intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	3 years	3 years
Maximum [Member] | Proprietary Knowledge [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	15 years	15 years
Maximum [Member] | Trademarks [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	20 years	20 years
Maximum [Member] | Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	19 years	19 years
Maximum [Member] | Other intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Acquired finite lived intangible asset useful life	15 years	15 years

Composition of Certain Balanc_3

Composition of Certain Balance Sheet Accounts - Summary of Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Allowance For Credit Loss [Abstract]
Beginning balance	$ 1,074	$ 1,338	$ 1,109	$ 1,332
Provision	98	149	63	155
Ending balance	$ 1,172	$ 1,487	$ 1,172	$ 1,487

Composition of Certain Balanc_4

Composition of Certain Balance Sheet Accounts - Summary of Accrued Expenses and Other Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Accrued Liabilities And Other Liabilities [Abstract]
Employee related liabilities	$ 24,590	$ 32,996
Customer deposits	10,676
Lease liability - operating	5,018	3,906
Marketing	3,847	3,421
Warranty	3,218	2,992
Construction in progress	8,421	4,068
Professional fees	1,737	2,296
Freight	2,211	2,292
Lease liability - finance	1,217	71
Other	4,651	4,480
Total accrued expenses and other current liabilities	$ 65,586	$ 56,522

Debt - Summary of Long-Term Deb

Debt - Summary of Long-Term Debt (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 507,654	$ 467,654
Less unamortized deferred financing costs	(2,117)	(2,625)
Less unamortized original issue discount	(253)	(314)
Long-term debt—less current portion and unamortized deferred financing costs	505,284	464,715
Term Loan
Debt Instrument [Line Items]
Long-term Debt, Gross	467,654	467,654
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	40,000
Less unamortized deferred financing costs	$ (1,000)	$ (1,200)

Debt - Summary of Long-Term D_2

Debt - Summary of Long-Term Debt (Detail) (Parenthetical)	6 Months Ended	12 Months Ended
	Mar. 31, 2022	Sep. 30, 2021
Debt Instrument [Line Items]
Debt instrument maturity date	May 5, 2024
Term Loan
Debt Instrument [Line Items]
Debt instrument maturity date	May 5, 2024
Debt instrument, description of variable rate basis	LIBOR + 2.50	LIBOR + 2.50
Debt instrument, basis spread on variable rate	2.50%	2.50%
Debt instrument rate	3.25%	3.25%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument maturity date	Mar. 31, 2026
Debt instrument, description of variable rate basis	LIBOR + 1.25
Debt instrument, basis spread on variable rate	1.25%
Debt instrument rate	2.25%

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($) $ in Thousands	Feb. 02, 2021	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2021
Debt Instrument [Line Items]
Debt instrument maturity date				May 5, 2024
Term loan outstanding		$ 507,654		$ 507,654		$ 467,654
Deferred financing cost		2,117		$ 2,117		2,625
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument maturity date				Mar. 31, 2026
Term loan outstanding		40,000		$ 40,000
Debt instrument, description of variable rate basis				LIBOR + 1.25
Debt instrument interest rate description				interest rate has been reduced by 25 basis points to (i) for ABR borrowings, the highest of (a) the Federal Funds Rate plus 50 basis points, (b) the prime rate and (c) the LIBOR as of such date for a deposit in U.S. dollars with a maturity of one month plus 100 basis points, plus, in each case, a spread of 25 to 75 basis points, based on average historical availability, or (ii) for Eurocurrency borrowings, adjusted LIBOR plus a spread of 125 to 175 basis points, based on average historical availability.
Debt instrument, basis spread on variable rate				1.25%
Deferred financing cost		1,000		$ 1,000		1,200
Aggregate maximum borrowing capacity		150,000		150,000
Outstanding letters of credit		2,800		2,800		3,300
Option to increase the commitments		$ 100,000		100,000
Line of credit facility, commitment fee description		If the average daily used percentage is greater than 50%, the commitment fee equals 25 basis points, and if the average daily used percentage is less than or equal to 50%, the commitment fee equals 37.5 basis points.
Line of credit facility, commitment fee amount		$ 100	$ 100	$ 200	$ 300
Debt instrument, covenant description				(i) 10% of the lesser of the aggregate commitments under the Revolving Credit Facility and the borrowing base, and (ii) $12.5 million
Maximum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument maturity date				Mar. 31, 2026
Minimum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument maturity date				May 9, 2022
Term Loan Agreement [Member]
Debt Instrument [Line Items]
Debt instrument maturity date				May 5, 2024
Debt instrument interest rate description				(i) the ABR floor by 25 basis points from 2.0% to 1.75%, (ii) the Adjusted LIBOR Rate floor by 25 basis points from 1.0% to 0.75% and (iii) the Applicable Margin with respect to any Effective Date Term Loans, by up to 125 basis points from 3.75% to 2.50% in the case of any Eurocurrency Loan and by up to 125 basis points from 2.75% to 1.50% in the case of any ABR Loan. The Applicable Margin may be reduced by a further 25 basis points in respect of both Eurocurrency Loans and ABR Loans during any period that the Borrower maintains specified public corporate family ratings.
Term Loan Agreement [Member] | ABR Floor [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis				ABR floor by 25 basis points from 2.0% to 1.75%
Term Loan Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis				Adjusted LIBOR Rate floor by 25 basis points from 1.0% to 0.75%
Term Loan Agreement [Member] | Eurocurrency Loan [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis				Term Loans, by up to 125 basis points from 3.75% to 2.50% in the case of any Eurocurrency Loan
Term Loan Agreement [Member] | ABR Loan [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis				up to 125 basis points from 2.75% to 1.50% in the case of any ABR Loan
Term Loan Agreement [Member] | Maximum [Member] | ABR Floor [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.00%
Term Loan Agreement [Member] | Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.00%
Term Loan Agreement [Member] | Maximum [Member] | Eurocurrency Loan [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	3.75%
Term Loan Agreement [Member] | Maximum [Member] | ABR Loan [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.75%
Term Loan Agreement [Member] | Minimum [Member] | ABR Floor [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.75%
Term Loan Agreement [Member] | Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	0.75%
Term Loan Agreement [Member] | Minimum [Member] | Eurocurrency Loan [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.50%
Term Loan Agreement [Member] | Minimum [Member] | ABR Loan [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.50%
CPG International LLC [Member]
Debt Instrument [Line Items]
Outstanding borrowings capacity		40,000		$ 40,000		0
Debt instrument, covenant description				CPG International LLC is also required to make mandatory prepayments (i) when aggregate borrowings exceed commitments or the applicable borrowing base and (ii) during “cash dominion,” which occurs if (a) the availability under the Revolving Credit Facility is less than the greater of (i) $12.5 million and (ii) 10% of the lesser of (x) $150.0 million and (y) the borrowing base, for five consecutive business days or (b) certain events of default have occurred and are continuing.
CPG International LLC [Member] | Amended Agreement For Term Loan | Wilmington Trust National Association
Debt Instrument [Line Items]
Deferred financing cost		2,100		$ 2,100		2,600
Term loan frequency of instalment payment				quarterly installments
Percentage of principal amount to be repaid by way of instalments				0.25253%
CPG International LLC [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Available borrowing capacity		107,200		$ 107,200
CPG International LLC [Member] | Maximum [Member]
Debt Instrument [Line Items]
Minimum fixed charge coverage ratio				100
CPG International LLC [Member] | Minimum [Member]
Debt Instrument [Line Items]
Minimum fixed charge coverage ratio				100
CPG International LLC [Member] | Term Loan Agreement [Member]
Debt Instrument [Line Items]
Term loan outstanding		$ 467,700		$ 467,700		$ 467,700
Abr Borrowings | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument interest rate description				(i) for ABR borrowings, the highest of (a) the Federal Funds Rate plus 50 basis points, (b) the prime rate and (c) the LIBOR as of such date for a deposit in U.S. dollars with a maturity of one month plus 100 basis points, plus, in each case, a spread of 25 to 75 basis points, based on average historical availability, or (ii) for Eurocurrency borrowings, adjusted LIBOR plus a spread of 125 to 175 basis points, based on average historical availability.
Abr Borrowings | London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis				LIBOR as of such date for a deposit in U.S. dollars with a maturity of one month plus 100 basis points, plus, in each case, a spread of 25 to 75 basis points
Abr Borrowings | Fed Funds Effective Rate Overnight Index Swap Rate [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis				Federal Funds Rate plus 50 basis points
Abr Borrowings | Prime Rate [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis				prime rate
Eurocurrency Borrowings [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument interest rate description				for Eurocurrency borrowings, adjusted LIBOR plus a spread of 125 to 175 basis points, based on average historical availability
Eurocurrency Borrowings [Member] | London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis				LIBOR plus a spread of 125 to 175 basis points

Debt - Summary of Interest Expe

Debt - Summary of Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Interest Expense
Other	$ 818	$ 204	$ 1,684	$ 408
Amortization - Debt issue costs
Capitalized interest	(1,216)	(451)	(2,327)	(936)
Interest expense	4,010	6,348	8,158	12,374
Term Loan
Interest Expense
Interest Expense, debt	3,798	4,423	7,682	10,100
Amortization - Debt issue costs
Amortization of debt issuance costs	254	1,698	508	1,989
Term Loan OID	30	97	61	132
Revolving Credit Facility [Member]
Interest Expense
Interest Expense, debt	260	154	419	317
Amortization - Debt issue costs
Amortization of debt issuance costs	$ 66	$ 223	$ 131	$ 364

Product Warranties - Additional

Product Warranties - Additional Information (Detail)	6 Months Ended
	Mar. 31, 2022
Product Warranties Disclosures [Abstract]
Assurance of product	The Company provides product assurance warranties of various lengths ranging from 5 years to lifetime for limited coverage for a variety of material and workmanship defects based on standard terms and conditions between the Company and its customers.

Product Warranties - Summary of

Product Warranties - Summary of Warranty Reserve Activity (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Product Warranties Disclosures [Abstract]
Beginning balance	$ 12,681	$ 11,044	$ 12,699	$ 10,913
Adjustments to reserve	1,810	1,827	2,277	2,550
Warranty claims payment	(543)	(817)	(1,028)	(1,426)
Accretion - purchase accounting valuation		11		28
Ending balance	13,948	12,065	13,948	12,065
Current portion of accrued warranty	(3,218)	(2,809)	(3,218)	(2,809)
Accrued warranty – less current portion	$ 10,730	$ 9,256	$ 10,730	$ 9,256

Leases - Additional Information

Leases - Additional Information (Detail)	Mar. 31, 2022
Minimum [Member]
Lessee Lease Description [Line Items]
Renewal options range	1 year
Maximum [Member]
Lessee Lease Description [Line Items]
Renewal options range	20 years

Leases - Summary of Lease Asset

Leases - Summary of Lease Assets and Lease Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021	Oct. 01, 2020
Assets
ROU operating lease assets	$ 21,180	$ 19,431
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Finance lease assets	$ 53,906	$ 49,084
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Total lease assets	$ 75,086	$ 68,515	$ 15,200
Current liabilities
Lease liability - operating	$ 5,018	$ 3,906
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	AccruedExpensesAndOtherLiabilitiesCurrent	AccruedExpensesAndOtherLiabilitiesCurrent
Lease liability - finance	$ 1,217	$ 71
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	AccruedExpensesAndOtherLiabilitiesCurrent	AccruedExpensesAndOtherLiabilitiesCurrent
Non-Current liabilities
Operating	$ 19,100	$ 18,585
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other non-current liabilities	Other non-current liabilities
Finance	$ 55,996	$ 50,590
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other non-current liabilities	Other non-current liabilities
Total lease liabilities	$ 81,331	$ 73,152	$ 18,700

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Leases [Abstract]
Operating lease expense	$ 1,454	$ 999	$ 2,624	$ 1,783
Finance lease amortization of assets	797	276	1,514	524
Finance lease interest on lease liabilities	868	203	1,673	406
Short term	171	28	218	53
Sublease income	(87)	(119)	(206)	(189)
Total lease expense	$ 3,203	$ 1,387	$ 5,823	$ 2,577

Leases - Supplemental Informati

Leases - Supplemental Information related to Leases (Detail)	Mar. 31, 2022	Sep. 30, 2021
Weighted-average remaining lease term
Operating leases	7 years	7 years 9 months 18 days
Finance leases	30 years 8 months 12 days	32 years 2 months 12 days
Weighted-average discount rate
Operating leases	4.10%	4.30%
Finance leases	6.30%	6.50%

Leases - Summary of Maturities

Leases - Summary of Maturities of Lease Liabilities (Detail) $ in Thousands	Mar. 31, 2022USD ($)
Operating Leases
2022	$ 2,954
2023	5,763
2024	4,592
2025	3,503
2026	2,250
Thereafter	9,291
Total lease payments	28,353
Less: Interest	(4,235)
Present Value of lease liability	24,118
Finance Leases
2022	2,248
2023	4,661
2024	4,375
2025	4,166
2026	3,963
Thereafter	105,243
Total lease payments	124,656
Less: Interest	(67,443)
Present Value of lease liability	57,213
Total
2022	5,202
2023	10,424
2024	8,967
2025	7,669
2026	6,213
Thereafter	114,534
Total lease payments	153,009
Less: Interest	(71,678)
Present Value of lease liability	$ 81,331

Fair Value Of Financial Instr_3

Fair Value Of Financial Instruments - Summary of Carrying Values and the Estimated Fair Values of the Debt Financial Instruments (Detail) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2022	Sep. 30, 2021
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Debt instrument maturity date	May 5, 2024
Revolving Credit Facility [Member]
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Debt instrument maturity date	Mar. 31, 2026
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member]
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Loans payable	$ 467,654	$ 467,654
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Revolving Credit Facility [Member]
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Loans payable	40,000
Estimated Fair Value [Member] | Fair Value, Inputs, Level 2 [Member]
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Loans payable	463,071	$ 467,420
Estimated Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Revolving Credit Facility [Member]
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Loans payable	$ 40,000

Fair Value Of Financial Instr_4

Fair Value Of Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2022	Mar. 31, 2022	Dec. 29, 2021
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Increase in fair value contingent payment	$ 11.7	$ 11.7
Contingent payment compensation expense	2.9	2.9
StruXure Outdoor, LLC [Member]
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Contingent payment arrangements, range of outcomes, value, low	0	0
Contingent payment arrangements, range of outcomes, value, high	$ 13.9	$ 13.9
Fair value of contingent payment			$ 9.5

Segments - Additional Informati

Segments - Additional Information (Detail)	6 Months Ended
	Mar. 31, 2022Segment
Segment Reporting [Abstract]
Number of Reportable Segments	2

Segments - Summary of Residenti

Segments - Summary of Residential and Commercial Segment Reporting Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Net sales to customers	$ 396,255	$ 293,121	$ 655,963	$ 505,399
Adjusted EBITDA
Total Adjusted EBITDA for reporting segments	107,025	85,413	181,204	147,505
Unallocated net expenses	(16,104)	(13,902)	(31,763)	(27,542)
Adjustments to Income (loss) before income tax provision
Depreciation and amortization	(29,042)	(25,271)	(57,124)	(49,549)
Stock-based compensation costs	(4,928)	(7,156)	(8,944)	(10,136)
Acquisition costs	(5,136)		(5,633)
Initial public offering costs and Secondary offering costs		(1,149)		(1,149)
Other costs	(177)	(1,390)	(662)	(3,053)
Interest expense, net	(4,010)	(6,348)	(8,158)	(12,374)
Income (loss) before income taxes	47,628	30,197	68,920	43,702
Residential [Member]
Segment Reporting Information [Line Items]
Net sales to customers	350,358	262,198	571,491	447,838
Adjusted EBITDA
Total Adjusted EBITDA for reporting segments	98,350	81,699	167,781	140,475
Commercial [Member]
Segment Reporting Information [Line Items]
Net sales to customers	45,897	30,923	84,472	57,561
Adjusted EBITDA
Total Adjusted EBITDA for reporting segments	$ 8,675	$ 3,714	$ 13,423	$ 7,030

Segments - Summary of Residen_2

Segments - Summary of Residential and Commercial Segment Reporting Information (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Business Transformation Costs [Line Items]
Business acquisition acquisition costs completed acquisitions	$ 3.9		$ 4.4
Inventory step up adjustments relating to business acquisitions	1.2		1.2
Legal expenses	0.1	$ 0.5	0.4	$ 1
Other costs, other	$ 0.1		0.2
Lease impact		0.2		0.4
IPO [Member]
Business Transformation Costs [Line Items]
Costs related to an incentive plan		$ 0.7	$ 0.1	$ 1.7

Capital Stock - Additional Info

Capital Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Jun. 01, 2021	Jan. 26, 2021	Jun. 16, 2020	Mar. 31, 2022	Sep. 30, 2021
Class Of Stock [Line Items]
Proceeds from initial public offering, net of related costs			$ 819.7
Underwriting commission and discounts			50.6
Estimated offering expenses payable			$ 9.2
Preferred stock, shares authorized				1,000,000	1,000,000
Preferred stock, par value per share				$ 0.001	$ 0.001
Common stock description of voting rights				The Class A common stock and Class B common stock provide identical economic rights, but holders of Class B common stock have limited voting rights, specifically that such holders have no right to vote, solely with respect to their shares of Class B common stock, with respect to the election, replacement or removal of directors.
Common stock description of conversion rights				Class A common stock and Class B common stock are not entitled to preemptive rights. Holders of Class B common stock may convert their shares of Class B common stock into shares of Class A common stock on a one-for-one basis, in whole or in part, at any time and from time to time at their option.
Conversion of Units of Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted				108,162,741
Conversion of Membership Interests in Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted				108,162,741
Common Class A [Member]
Class Of Stock [Line Items]
Common stock, shares authorized				1,100,000,000	1,100,000,000
Common stock, par value per share				$ 0.001	$ 0.001
Common Class A [Member] | Conversion of Units of Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted				75,093,778
Common Class A [Member] | Conversion of Membership Interests in Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted				75,093,778
Common Class A [Member] | Conversion of Profit Interests [Member]
Class Of Stock [Line Items]
Common stock member interests converted				2,703,243
Common Class B [Member]
Class Of Stock [Line Items]
Common stock, shares authorized				100,000,000	100,000,000
Common stock, par value per share				$ 0.001	$ 0.001
Common Class B [Member] | Conversion of Units of Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted				33,068,963
Common Class B [Member] | Conversion of Membership Interests in Limited Liability Company [Member]
Class Of Stock [Line Items]
Common stock member interests converted				33,068,963
Class A Restricted Stock [Member] | Conversion of Profit Interests [Member]
Class Of Stock [Line Items]
Common stock member interests converted				5,532,057
IPO [Member]
Class Of Stock [Line Items]
Shares issued price			$ 23
IPO [Member] | Common Class A [Member]
Class Of Stock [Line Items]
Shares issued during period			38,237,500
Over-Allotment Option [Member]
Class Of Stock [Line Items]
Shares issued during period			4,987,500
Over-Allotment Option [Member] | Common Class A [Member]
Class Of Stock [Line Items]
Shares issued price	$ 43.50	$ 40
Overallotment stock shares sold by shareholders during the period	2,250,000	3,000,000
Employee Stock [Member] | Common Class A [Member]
Class Of Stock [Line Items]
Common stock shares reserved for future issuance				3,477,413
Secondary Offering [Member] | Common Class A [Member]
Class Of Stock [Line Items]
Common stock, par value per share	$ 0.001	$ 0.001
Stock shares sold by shareholders during the period	17,250,000	23,000,000
Estimated offering expenses	$ 1.1	$ 1.2

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation expenses	$ 4,928	$ 7,156	$ 8,944	$ 10,136
Income tax benefit stock based compensation expenses	1,100	300	1,900	800
Unvested stock compensation not recognised	35,600		$ 35,600
Unvested stock awards weighted average remaining period of recognition			2 years 3 months 18 days
Selling, General and Administrative Expenses [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation expenses	$ 4,900	$ 7,200	$ 8,900	$ 10,100
2020 Omnibus Incentive Compensation Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum number of shares authorised under share based compensation plan	15,852,319		15,852,319
Common stock shares reserved for future issuance	3,849,011		3,849,011
Stock based compensation period of expiry of stock options			10 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Share-Based Payment Award Valuation Assumptions (Detail)	6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate	1.34%	0.56%
Expected volatility	40.00%	35.00%
Expected term (in years)	6 years	6 years
Expected dividend yield	0.00%	0.00%

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Option Activities (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Mar. 31, 2022
Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Option, Outstanding	1,556,489
Number of Option, Granted
Number of Option, Exercised	(123,008)
Number of Option, Cancelled/Forfeited	(2)
Number of Option, Outstanding	1,433,479
Number of Option, Vested and exercisable	1,433,479
Weighted Average Exercise Price Per Share, Outstanding	$ 23
Weighted Average Exercise Price Per Share, Granted	0
Weighted Average Exercise Price Per Share, Exercised	23
Weighted Average Exercise Price Per Share, Cancelled/Forfeited	23
Weighted Average Exercise Price Per Share, Outstanding	23
Weighted Average Exercise Price Per Share, Vested and exercisable	$ 23
Weighted Average Remaining Contract Term, Outstanding	8 years 2 months 12 days
Weighted Average Remaining Contract Term, Vested and exercisable	8 years 2 months 12 days
Weighted Average Intrinsic Value, Outstanding	$ 2,638
Weighted Average Intrinsic Value, Vested and exercisable	$ 2,638
Service Based Stock Option Activity [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Option, Outstanding	3,434,221
Number of Option, Granted	324,768
Number of Option, Exercised	(91,033)
Number of Option, Cancelled/Forfeited	(41,410)
Number of Option, Outstanding	3,626,546
Number of Option, Vested and exercisable	1,662,842
Weighted Average Exercise Price Per Share, Outstanding	$ 23.82
Weighted Average Exercise Price Per Share, Granted	42.79
Weighted Average Exercise Price Per Share, Exercised	23
Weighted Average Exercise Price Per Share, Cancelled/Forfeited	24.74
Weighted Average Exercise Price Per Share, Outstanding	25.53
Weighted Average Exercise Price Per Share, Vested and exercisable	$ 23.24
Weighted Average Remaining Contract Term, Outstanding	8 years 3 months 18 days
Weighted Average Remaining Contract Term, Vested and exercisable	8 years
Weighted Average Intrinsic Value, Outstanding	$ 5,675
Weighted Average Intrinsic Value, Vested and exercisable	$ 2,993

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Stock Awards Activity Other Than Options (Detail)	6 Months Ended
	Mar. 31, 2022$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Outstanding and unvested	366,852
Number of Shares, Granted	224,900
Number of Shares, Vested	(51,154)
Number of Shares, Forfeited	(22,669)
Number of Shares, Outstanding and unvested	517,929
Weighted Average Grant Date Fair Value, Outstanding and unvested | $ / shares	$ 30.42
Weighted Average Grant Date Fair Value, Granted | $ / shares	37.85
Weighted Average Grant Date Fair Value, Vested | $ / shares	35.99
Weighted Average Grant Date Fair Value, Outstanding and unvested | $ / shares	$ 33.18
Service Based Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Outstanding and unvested	717,580
Number of Shares, Granted
Number of Shares, Vested	(245,308)
Number of Shares, Forfeited	(10,573)
Number of Shares, Outstanding and unvested	461,699
Weighted Average Grant Date Fair Value, Outstanding and unvested | $ / shares	$ 23
Weighted Average Grant Date Fair Value, Granted | $ / shares
Weighted Average Grant Date Fair Value, Vested | $ / shares	23
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	23
Weighted Average Grant Date Fair Value, Outstanding and unvested | $ / shares	$ 23
Performance Based Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Outstanding and unvested	111,804
Number of Shares, Granted	115,608
Number of Shares, Vested
Number of Shares, Forfeited	(6,295)
Number of Shares, Outstanding and unvested	221,117
Weighted Average Grant Date Fair Value, Outstanding and unvested | $ / shares	$ 35
Weighted Average Grant Date Fair Value, Granted | $ / shares	41.21
Weighted Average Grant Date Fair Value, Vested | $ / shares
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	35.47
Weighted Average Grant Date Fair Value, Outstanding and unvested | $ / shares	$ 38.23

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Restricted Stock Unit Awards Activity (Detail)	6 Months Ended
	Mar. 31, 2022$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Outstanding and unvested | shares	366,852
Number of Shares, Granted | shares	224,900
Number of Shares, Vested | shares	(51,154)
Number of Shares, Forfeited | shares	(22,669)
Number of Shares, Outstanding and unvested | shares	517,929
Weighted Average Grant Date Fair Value, Outstanding and unvested | $ / shares	$ 30.42
Weighted Average Grant Date Fair Value, Granted | $ / shares	37.85
Weighted Average Grant Date Fair Value, Vested | $ / shares	35.99
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	30.82
Weighted Average Grant Date Fair Value, Outstanding and unvested | $ / shares	$ 33.18

Earnings Per Share - Summary of

Earnings Per Share - Summary of Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net income (loss)	$ 35,818	$ 22,640	$ 52,525	$ 32,788
Net income (loss) attributable to common stockholders- basic and diluted	$ 35,818	$ 22,640	$ 52,525	$ 32,788
Denominator:
Basic	154,661,277	153,509,612	154,551,589	153,366,516
Diluted	156,121,476	156,747,514	156,560,502	156,377,902
Net income (loss) per common share - basic	$ 0.23	$ 0.15	$ 0.34	$ 0.21
Net income (loss) per common share - diluted	$ 0.23	$ 0.14	$ 0.34	$ 0.21

Earnings Per Share - Summary _2

Earnings Per Share - Summary of Antidilutive Securities Excluded From Computation of Earnings Per Share (Detail) - shares	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	535,161	117,989	388,946	76,498
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	303,624	2,607	204,607	1,289

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Effective income tax reconciliation percentage	24.80%	25.00%	23.80%	25.00%

Commitments And Contingencies -

Commitments And Contingencies - Additional Information (Detail) - Workmen Compensation [Member] $ in Millions	Sep. 30, 2019USD ($)
Minimum [Member]
Loss Contingencies [Line Items]
Estimate Of Possible Loss	$ 0.4
Maximum [Member]
Loss Contingencies [Line Items]
Estimate Of Possible Loss	$ 0.5

Condensed Financial Informati_3

Condensed Financial Information of Registrant (Parent Company Only) - Schedule of Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020
Non-current assets:
Total assets	$ 2,319,480		$ 2,187,834
LIABILITIES AND STOCKHOLDERS' EQUITY:
Total liabilities	826,446		760,670
Stockholders' equity:
Preferred stock, $0.001 par value; 1,000,000 shares authorized and no shares issued and outstanding at March 31, 2022 and at September 30, 2021, respectively
Additional paid‑in capital	1,628,581		1,615,236
Accumulated deficit	(135,702)		(188,227)
Total stockholders' equity	1,493,034	$ 1,451,151	1,427,164	$ 1,351,448	$ 1,321,166	$ 1,303,888
Total liabilities and stockholders' equity	2,319,480		2,187,834
Parent Company [Member]
Non-current assets:
Investments in subsidiaries	1,493,034		1,427,164
Total non-current assets	1,493,034		1,427,164
Total assets	1,493,034		1,427,164
Stockholders' equity:
Preferred stock, $0.001 par value; 1,000,000 shares authorized and no shares issued and outstanding at March 31, 2022 and at September 30, 2021, respectively
Additional paid‑in capital	1,628,581		1,615,236
Accumulated deficit	(135,702)		(188,227)
Total stockholders' equity	1,493,034		1,427,164
Total liabilities and stockholders' equity	1,493,034		1,427,164
Common Class A [Member]
Stockholders' equity:
Common stock value	155		155
Common Class A [Member] | Parent Company [Member]
Stockholders' equity:
Common stock value	$ 155		$ 155

Condensed Financial Informati_4

Condensed Financial Information of Registrant (Parent Company Only) - Schedule of Balance Sheets (Parenthetical) (Detail) - $ / shares	Mar. 31, 2022	Sep. 30, 2021
Preferred stock, par value per share	$ 0.001	$ 0.001
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Class A [Member]
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	1,100,000,000	1,100,000,000
Common stock, shares issued	155,108,627	154,866,313
Common stock, shares outstanding	155,108,627	154,866,313
Common Class B [Member]
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	100	100
Common stock, shares outstanding	100	100
Parent Company [Member]
Preferred stock, par value per share	$ 0.001	$ 0.001
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Parent Company [Member] | Common Class A [Member]
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	1,100,000,000	1,100,000,000
Common stock, shares issued	155,108,627	154,866,313
Common stock, shares outstanding	155,108,627	154,866,313
Parent Company [Member] | Common Class B [Member]
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	100	100
Common stock, shares outstanding	100	100

Condensed Financial Informati_5

Condensed Financial Information of Registrant (Parent Company Only) - Schedule of Statements of Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Condensed Statement of Income Captions [Line Items]
Comprehensive income (loss)	$ 35,818	$ 22,640	$ 52,525	$ 32,788
Parent Company [Member]
Condensed Statement of Income Captions [Line Items]
Net income (loss) of subsidiaries	35,818	22,640	52,525	32,788
Comprehensive income (loss)	$ 35,818	$ 22,640	$ 52,525	$ 32,788

Condensed Financial Informati_6

Condensed Financial Information of Registrant (Parent Company Only) - Additional Information (Detail) - Parent Company [Member] - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Condensed Statement of Income Captions [Line Items]
Minimum threshold percentage of restricted net assets	25.00%		25.00%
Cash dividends paid	$ 0	$ 0	$ 0	$ 0

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($)	Apr. 28, 2022	Mar. 31, 2022	May 05, 2022	Sep. 30, 2021
Subsequent Event [Line Items]
Term loan outstanding		$ 507,654,000		$ 467,654,000
Term loan agreement maturity date		May 5, 2024
Subsequent Event | Common Class A [Member] | Maximum [Member]
Subsequent Event [Line Items]
Stock repurchase program, authorized amount			$ 400,000,000
2022 Term Loan Agreement
Subsequent Event [Line Items]
Debt instrument interest rate description		The 2022 Term Loan Agreement will mature on April 28, 2029 and the loans thereunder bear an interest rate equal to (i) in the case of ABR borrowings, the highest of (a) the Federal Funds Rate plus 0.50%, (b) the Prime Rate as in effect on such day and (c) the one-month Term SOFR rate plus 1.00% per annum, provided that in no event will the alternative base rate be less than 1.50% per annum, plus an applicable margin of 1.50% and (ii) in the case of SOFR borrowings, the Term SOFR rate for the applicable interest period, in each case, plus an applicable margin of 2.50%.  The 2022 Term Loan Agreement contains customary affirmative and negative covenants for credit facilities of this type.
2022 Term Loan Agreement | Subsequent Event
Subsequent Event [Line Items]
Term loan outstanding	$ 600,000,000
Term loan agreement maturity date	Apr. 28, 2029
Debt instrument, basis spread on variable rate	2.50%
Applicable margin rate	1.50%
Federal Funds Rate | 2022 Term Loan Agreement | Subsequent Event
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate	0.50%
Term SOFR | 2022 Term Loan Agreement | Subsequent Event
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate	1.00%
Alternative Base Rate | 2022 Term Loan Agreement | Subsequent Event
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate	1.50%