The AZEK Company Inc. (AZEK) 10-Q 12 Feb 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Dec. 31, 2020	Jan. 29, 2021
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2021
Document Period End Date	Dec. 31, 2020
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	Non-accelerated Filer
Entity Small Business	false
Entity Incorporation, State or Country Code	DE
Entity Emerging Growth Company	true
Entity Ex Transition Period	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
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		154,740,154
Common Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		100

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Current assets:
Cash and cash equivalents	$ 210,034	$ 215,012
Trade receivables, net of allowances	41,234	70,886
Inventories	166,151	130,070
Prepaid expenses	11,412	8,367
Other current assets	161	360
Total current assets	428,992	424,695
Property, plant and equipment, net	279,183	261,774
Goodwill	951,390	951,390
Intangible assets, net	279,731	292,374
Other assets	1,608	1,623
Total assets	1,940,904	1,931,856
Current liabilities:
Accounts payable	38,179	42,059
Accrued rebates	35,754	30,362
Accrued interest	1,089	1,103
Current portion of long-term debt obligations
Accrued expenses and other liabilities	39,408	50,516
Total current liabilities	114,430	124,040
Deferred income taxes	24,168	21,260
Finance lease obligations — less current portion	10,886	10,910
Long-term debt — less current portion	463,308	462,982
Other non-current liabilities	9,009	8,776
Total liabilities	621,801	627,968
Commitments and contingencies (See Note 15)
Stockholders' equity:
Preferred stock, $0.001 par value; 1,000,000 shares authorized and no shares issued and outstanding at December 31, 2020 and at September 30, 2020, respectively
Additional paid-in capital	1,592,240	1,587,208
Accumulated deficit	(273,292)	(283,475)
Total stockholders' equity	1,319,103	1,303,888
Total liabilities and stockholders' equity	1,940,904	1,931,856
Common Class A [Member]
Stockholders' equity:
Common stock	155	155
Total stockholders' equity	155	155
Common Class B [Member]
Stockholders' equity:
Common stock
Total stockholders' equity

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Sep. 30, 2020
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	154,735,617	154,637,240
Common stock, shares outstanding	154,735,617	154,637,240
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
	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net sales	$ 212,278	$ 166,043
Cost of sales	139,302	114,752
Gross profit	72,976	51,291
Selling, general and administrative expenses	53,029	43,473
Other general expenses	0	1,978
Loss (gain) on disposal of plant, property and equipment	212	(73)
Operating income (loss)	19,735	5,913
Other expenses:
Interest expense	6,196	19,759
Total other expenses	6,196	19,759
Income (loss) before income taxes	13,539	(13,846)
Income tax expense (benefit)	3,356	(4,000)
Net income (loss)	$ 10,183	$ (9,846)
Net income (loss) per common share:
Basic	$ 0.07	$ (0.09)
Diluted	$ 0.07	$ (0.09)
Comprehensive income (loss)	$ 10,183	$ (9,846)
Weighted average shares used in calculating net income (loss) per common share:
Basic	153,226,378	108,162,741
Diluted	156,018,731	108,162,741

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Adoption of ASU [Member]	Common Class A [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, 2019	$ 490,023		$ 75	$ 33	$ 652,493	$ (162,578)
Beginning balance (in shares) at Sep. 30, 2019			75,093,778	33,068,963
Adoption of ASU No. 2016-16		$ 1,336					$ 1,336
Net income (loss)	(9,846)					(9,846)
Stock-based compensation	684				684
Member redemptions prior to initial public offering	(2,201)				(2,201)
Ending balance at Dec. 31, 2019	479,996		$ 75	$ 33	650,976	(171,088)
Ending balance (in shares) at Dec. 31, 2019			75,093,778	33,068,963
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)	10,183					10,183
Stock-based compensation	2,878				2,878
Exercise of vested stock options	2,364				2,364
Exercise of vested stock options (in shares)			98,377
Initial public offering expenses	(210)				(210)
Ending balance at Dec. 31, 2020	$ 1,319,103		$ 155		$ 1,592,240	$ (273,292)
Ending balance (in shares) at Dec. 31, 2020			154,735,617	100

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net income (loss)	$ 10,183	$ (9,846)
Adjustments to reconcile net income (loss) to net cash flows provided by (used in) operating activities:
Depreciation expense	11,627	10,283
Amortization expense	12,643	13,858
Non-cash interest expense	467	997
Deferred income tax provision (benefit)	2,908	(2,653)
Non-cash compensation expense	2,878	1,056
Loss (gain) on disposition of property, plant and equipment	212	(73)
Changes in certain assets and liabilities:
Trade receivables	29,652	(2,923)
Inventories	(36,081)	(23,926)
Prepaid expenses and other current assets	(2,846)	296
Accounts payable	(5,097)	(25,042)
Accrued expenses and interest	(6,537)	(17,460)
Other assets and liabilities	106	(928)
Net cash provided by (used in) operating activities	20,115	(56,361)
Investing activities:
Purchases of property, plant and equipment	(27,021)	(19,131)
Proceeds from sale of property, plant and equipment	17	113
Net cash provided by (used in) investing activities	(27,004)	(19,018)
Financing activities:
Payments on long-term debt obligations		(2,076)
Proceeds (repayments) of finance lease obligations	(243)	(193)
Exercise of vested stock options	2,364
Payments of initial public offering related costs	(210)	(3,630)
Redemption of capital contributions prior to initial public offering		(2,201)
Net cash provided by (used in) financing activities	1,911	(8,100)
Net increase (decrease) in cash and cash equivalents	(4,978)	(83,479)
Cash and cash equivalents at beginning of period	215,012	105,947
Cash and cash equivalents at end of period	210,034	22,468
Supplemental cash flow disclosure:
Cash paid for interest, net of amounts capitalized	5,847	25,045
Cash paid for income taxes, net of refunds	(56)	6
Supplemental non-cash investing and financing disclosure:
Capital expenditures in accounts payable at end of period	4,035	2,007
Property, plant and equipment acquired under finance leases	$ 334	$ 446

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	3 Months Ended
	Dec. 31, 2020
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”) 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 a leading manufacturer of premium, low-maintenance non-fabricated Initial Public Offering On June 16, 2020, the Company completed its initial public offering (the “IPO”) of its Class A common stock, in which it sold 38,237,500 shares, including 4,987,500 shares pursuant to the underwriters’ over-allotment option. The shares began trading on the New York Stock Exchange on June 12, 2020 under the symbol “AZEK”. 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. In addition, the Company used its net proceeds to redeem $350.0 million in aggregate principal of its then-outstanding 2025 Senior Notes, $70.0 million of its then-outstanding principal amount under the Revolving Credit Facility and effected a $337.7 million prepayment of its then-outstanding principal amount under the Term Loan Agreement. In conjunction with the Company’s conversion from a limited liability company into a corporation (the “Corporate Conversion”) prior to the closing of the IPO, the Company effected a unit split of its then-outstanding limited liability company unit and then converted the units on a one-to-one Secondary Offering On September 15, 2020, the Company completed an offering of 28,750,000 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 3,750,000 additional shares of Class A common stock, at a public offering price of $33.25 per share. The shares were sold by certain stockholders of the Company (the “Selling Stockholders”). The Company did not receive any of the proceeds from the sale of the shares by the Selling Stockholders. Immediately subsequent to the closing of the secondary offering, Class B common stockholders converted 33,068,863 shares of Class B common stock into Class A common stock. In addition, the secondary offering triggered a change in performance criteria, in which certain performance-vested restricted stock awards and stock options vested as a result of the secondary offering. Refer to Note 11 and 12 for additional information. 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 and cash flows for the three months ended December 31, 2020 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 COVID-19 COVID-19 COVID-19 COVID-19 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 2020 Form 10-K. 10-K, 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 2020 Form 10-K 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 approximately $1.8 million and $2.1 million, respectively, for the three months ended December 31, 2020 and 2019. Recently Adopted Accounting Pronouncements Under the Jumpstart Our Business Startups (“JOBS”) Act, the Company qualifies as an emerging growth company (“EGC”) and as such, has elected not to opt out of the extended transition period for complying with new or revised accounting pronouncements. During the extended transition period, the Company is not subject to new or revised accounting standards applicable to public companies. The accounting pronouncements pending adoption below reflect effective dates for the Company as an EGC with the extended transition period. On October 1, 2019, the Company adopted ASU No. 2016-16, Income Taxes (Topic 740): Intra-Entity Transfer of Assets Other Than Inventory On October 1, 2020, the Company adopted ASU No. 2018-13, Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement, Fair Value Measurement Recently Issued Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-02, Leases (Topic 842), No. 2017-13, No. 2018-01, 2018-10 2018-11, No. 2018-20, No. 2019-01, No. 2019-10 No. 2020-05. right-of-use In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) No. 2019-05 2019-10 2019-11. off-balance In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-Use 350-40): internal-use In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740)—Simplifying the Accounting for Income Taxes In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848), Facilitation of the Effects of Reference Rate Reform on Financial Reporting

Revenue

Revenue	3 Months Ended
	Dec. 31, 2020
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 $35.8 million and $24.9 million as of December 31, 2020 and 2019, respectively, and contra trade receivables of $3.1 million and $2.2 million as of December 31, 2020 and 2019, respectively. The rebate activity was as follows (in thousands): Three Months Ended December 31, 2020 2019 Beginning balance $ 32,679 $ 24,858 Rebate expense 13,673 10,314 Rebate payments (7,533 ) (8,023 ) Ending balance $ 38,819 $ 27,149 The Company records deferred revenue when cash payments are received or due in advance of the Company’s performance.

Inventories

Inventories	3 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventories	3. 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 December 31, 2020 September 30, 2020 Raw materials $ 37,544 $ 33,850 Work in process 19,604 19,935 Finished goods 109,003 76,285 Total inventories $ 166,151 $ 130,070

Property, Plant and Equipment -

Property, Plant and Equipment - Net	3 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment - Net	4. PROPERTY, PLANT AND EQUIPMENT — Property, plant and equipment – net consisted of the following (in thousands): December 31, 2020 September 30, 2020 Land and improvements $ 2,758 $ 2,758 Buildings and improvements 73,080 71,059 Capital lease – building 2,021 2,021 Capital lease – manufacturing equipment 726 1,026 Capital lease – vehicles 4,356 3,782 Manufacturing equipment 324,287 306,036 Computer equipment 25,713 24,927 Furnitures and fixtures 5,809 5,689 Vehicles 465 465 Total property, plant and equipment 439,215 417,763 Construction in progress 61,748 54,412 500,963 472,175 Accumulated depreciation (221,780 ) (210,401 ) Total property, plant and equipment – net $ 279,183 $ 261,774 The Company is considered the owner, for accounting purposes only, of leased office space, as it had taken on certain risks of construction build cost overages above normal tenant improvement allowances. Accordingly, the estimated fair value of the leased property was $9.2 million as of both December 31, 2020 and September 30, 2020. The corresponding lease financing obligation was $7.9 million as of both December 31, 2020 and September 30, 2020. The lease financing obligation was recorded in “Finance lease obligations – less current portion” in the Condensed Consolidated Balance Sheets. Refer to Note 15 for additional information. Depreciation expense was approximately $11.6 m build-to-suit

Goodwill and Intangible Assets

Goodwill and Intangible Assets - Net	3 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets - Net	5. GOODWILL AND INTANGIBLE ASSETS—NET Goodwill As of both December 31, 2020 and September 30, 2020, the Company had goodwill of $951.4 million with carrying amounts for Residential of $911.0 million and Commercial of $40.4 million. As of December 31, 2020, total accumulated goodwill impairments were $32.2 million, all attributable to the Company’s Commercial segment. Intangible assets, net The Company does not have any indefinite lived intangible assets other than goodwill as of December 31, 2020 and September 30, 2020. Finite-lived intangible assets consisted of the following (in thousands): December 31, 2020 Lives in Gross Accumulated Net Propriety knowledge 10 — $ 289,300 $ (200,578 ) $ 88,722 Trademarks 5 — 20 223,840 (128,340 ) 95,500 Customer relationships 15 — 146,670 (55,246 ) 91,424 Patents 10 7,000 (3,436 ) 3,564 Other intangible assets 3 — 15 4,076 (3,555 ) 521 Total intangible assets $ 670,886 $ (391,155 ) $ 279,731 September 30, 2020 Lives in Gross Accumulated Net Propriety knowledge 10 — 15 $ 289,300 $ (195,303 ) $ 93,997 Trademarks 5 — 20 223,840 (124,521 ) 99,319 Customer relationships 15 — 19 146,670 (52,119 ) 94,551 Patents 10 7,000 (3,182 ) 3,818 Other intangible assets 3 — 15 4,076 (3,387 ) 689 Total intangible assets $ 670,886 $ (378,512 ) $ 292,374 Amortization expense was approximately $12.6 million and $13.9 million in the three months ended December 31, 2020 and 2019, respectively. As of December 31, 2020, the remaining weighted-average amortization period for acquired intangible assets was 12.8 years.

Composition of Certain Balance

Composition of Certain Balance Sheet Accounts	3 Months Ended
	Dec. 31, 2020
Composition of Certain Balance Sheet Accounts Disclosure [Abstract]
Composition of Certain Balance Sheet Accounts	Allowance for Doubtful Accounts Allowance for doubtful accounts consisted of the following (in thousands): December 31, 2020 September 30, 2020 Beginning balance $ 1,332 $ 904 Provision 6 512 Bad debt write-offs — (119 ) Acquisitions — 35 Ending balance $ 1,338 $ 1,332 Accrued Expenses and Other Liabilities Accrued expenses consisted of the following (in thousands): December 31, 2020 September 30, 2020 Employee related liabilities $ 18,555 $ 26,554 Freight 3,805 5,530 Professional fees 1,652 4,249 Marketing 2,859 3,343 Warranty 2,681 2,921 Construction in progress 2,054 1,303 Capital lease 1,047 969 Manufacturing related accrual s 2,776 1,664 Other 3,979 3,983 Total accrued expenses and other current liabilities $ 39,408 $ 50,516

Debt

Debt	3 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	7. DEBT Debt consisted of the following (in thousands): December 31, 2020 September 30, 2020 Term Loan Agreement due May 5, 2024 — LIBOR + 3.75% (4.75% and 4.75% at December 31, 2020 and September 30, 2020, respectively), (includes a discount of $472 and $507 at December 31, 2020 and September 30, 2020, respectively) $ 467,182 $ 467,147 Revolving Credit Facility through March 9, 2022 — LIBOR + 1.50% — — 2021 Senior Notes due October 1, 2021 — Fixed at 8% — — Total 467,182 467,147 Less unamortized deferred financing fees (3,874 ) (4,165 ) Less current portion — — Long-term debt — less current portion and unamortized financing fees $ 463,308 $ 462,982 As of December 31, 2020, the Company scheduled fiscal year debt payment on the Term Loan Agreement as $467.7 million in the year 2024. No other debt payments are due by the Company in any other fiscal year. Term Loan Agreement On September 30, 2013, CPG International LLC refinanced its then outstanding long-term debt and entered into (i) a new senior secured revolving credit facility (the “Revolving Credit Facility”) among CPG International LLC (as successor-in-interest successor-in-interest co-syndication co-documentation trustee. The proceeds from borrowings under the amended Term Loan Agreement and the 2021 Senior Notes were used to (i) fund the acquisition of CPG International LLC and (ii) repay all amounts outstanding under the Company’s prior term loan agreement, prior notes and related fees. The Term Loan Agreement matures on May 5, 2024, since the 2021 Senior Notes were redeemed June 8, 2020. 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 200 basis points, plus the applicable margin of 275 basis points per annum; or (ii) for Eurocurrency borrowings, the adjusted LIBOR 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) 100 basis points, plus the applicable margin of 375 basis points per annum. As of December 31, 2020, and September 30, 2020, unamortized deferred financing fees related to the Term Loan Agreement were $3.9 million and $4.2 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 Company used part of its net proceeds from the IPO to prepay outstanding principal of the Term Loan Agreement in the amount of $337.7 million. 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 AZEK Company Inc. and 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 “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. 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). The estimated prepayment of excess cash flow was declined by the lenders at September 30, 2020. 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. The Term Loan Agreement restricts payments of dividends unless certain conditions are met, as defined in the Term Loan Agreement. Revolving Credit Facility On March 9, 2017, CPG International LLC amended, restated and extended the maturity of the Revolving Credit Facility, and on June 5, 2020, CPG International LLC further amended the Revolving Credit Facility (the “Amendment”) to establish $8.5 million of commitments for FILO loans, which were available to be drawn in a single disbursement on or prior to December 31, 2020. We did not draw on the FILO Loans which expired on December 31, 2020. The Revolving Credit Facility matures on March 9, 2022. 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. The Company had no outstanding borrowings under the Revolving Credit Facility as of December 31, 2020 and September 30, 2020. In addition, the Company had $4.4 million and $6.8 million of outstanding letters of credit held against the Revolving Credit Facility as of December 31, 2020 and September 30, 2020, respectively. Deferred financing costs, net of accumulated amortization, related to the Revolving Credit Facility at December 31, 2020 and September 30, 2020 were $0.7 million and $0.8 million, respectively. CPG International LLC had approximately $ 143.3 The Revolving Credit Facility provides for an interest rate on outstanding principal thereunder at a fluctuating rate, at CPG International LLC’s option, at (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 50 to 100 basis points, based on average historical availability, or (ii) for Eurocurrency borrowings, adjusted LIBOR plus a spread of 150 200 50 The obligations under the Revolving Credit Facility are guaranteed by The AZEK Company Inc. 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 AZEK Company Inc., 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 December 31, 2020, 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. 2021 Senior Notes The 2021 Senior Notes were issued on September 30, 2013, in an aggregate principal amount of $315.0 million, and had a maturity of October 1, 2021. The 2021 Senior Notes bore interest at the rate of 8.000% per annum payable in cash semi-annually in arrears on April 1 and October 1 of each year (computed based on a 360-day 30-day 12-month 2016 106.0 % 2017 104.0 % 2018 102.0 % 2019 and thereafter 100.0 % The indenture relating to the 2021 Senior Notes contained negative covenants that are customary for financings of this type. The indenture did not contain any financial maintenance covenants. In connection with the 2025 Senior Notes offering, the Company issued a redemption notice on May 7, 2020 for the full $315.0 million of outstanding 2021 Senior Notes, which were redeemed on June 8, 2020. Interest expense consisted of the following (in thousands): Three Months Ended December 31, 2020 2019 Interest expense Term Loan Agreement $ 5,677 $ 12,143 2021 Senior Notes — 6,300 Revolving Credit Facility 165 153 Other 373 385 Amortization — — Debt issue costs Term Loan Agreement 291 495 2021 Senior Notes — 352 Revolving Credit Facility 141 89 Original issue discounts 35 60 Less capitalized interest (486 ) (218 ) Interest expense $ 6,196 $ 19,759 See Note 9 for the fair value of the Company’s debt as of December 31, 2020 and September 30, 2020.

Product Warranties

Product Warranties	3 Months Ended
	Dec. 31, 2020
Product Warranties Disclosures [Abstract]
Product Warranties	8. 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): December 31, December 31 2019 Beginning balance $ 10,913 $ 11,133 Adjustments to reserve 723 1,372 Warranty claims payment (608 ) (950 ) Accretion — purchase accounting valuation 16 33 Ending balance 11,044 11,588 Current portion of accrued warranty (2,681 ) (3,001 ) Accrued warranty — less current portion $ 8,363 $ 8,587 TimberTech Warranties and Related Indemnification In connection with the acquisition of TimberTech on September 21, 2012 and the acquisition of CPG International LLC on September 30, 2013, the Company recognized the fair value of the related warranty liabilities calculated as the net present value of the expected costs to settle all future warranty claims for products sold prior to the acquisition dates. The Company records accretion expense in “Cost of sales” in the Condensed Consolidated Statement of Comprehensive Income (Loss) in order to increase the value of the liability to reflect the future value of the warranty claims when they are actually settled. In addition, the Company records estimated warranty claims obligations related to current sales on an ongoing basis for the TimberTech product line. Pursuant to the TimberTech purchase agreement, the seller, Crane Group Companies Limited (“Crane”), also agreed to indemnify the Company for claims made up to seven years after the acquisition date for the majority of the costs to settle warranty claims for certain identified problems related to two products which have exhibited a high number of claims related to scorching and fading defects. The products were produced between 2010 and 2011 and have not been sold by the Company since 2011. Similar to its recognition of the warranty liability, the Company recorded an indemnification receivable from Crane on the acquisition date equal to the fair value of the indemnification calculated as the net present value of the expected indemnification payments to be received in the future. At both and The Company will continue to monitor the actual cost to settle warranty claims in the future and will make adjustments to the warranty liability and indemnification receivable if needed. The indemnification period expired on September 21, 2019. Crane disputes the scope of its past indemnification obligations and the Company cannot predict the outcome of the dispute. The Company may need to record additional charges to the Condensed Consolidated Statements of Comprehensive Income (Loss) and the Condensed Consolidated Balance Sheets related to the reserve and any obligations as a result of the indemnification dispute in future periods.

Fair Value Of Financial Instrum

Fair Value Of Financial Instruments	3 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Of Financial Instruments	9. 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): December 31, 2020 September 30, 2020 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Term Loan Agreement due May 5, 2024 $ 467,182 $ 467,182 $ 467,147 $ 465,185

Segments

Segments	3 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segments	10. 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 additions of Ultralox and Versatex are complementary to the Residential segment railing and trim businesses, respectively. The recent addition of Return Polymers provides a 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 months ended December 31 2020 and 2019 (in thousands). Three Months Ended December 31, 2020 2019 Net sales to customers Residential $ 185,640 $ 135,668 Commercial 26,638 30,375 Total $ 212,278 $ 166,043 Segment Adjusted EBITDA Residential $ 58,776 $ 38,915 Commercial 3,316 3,023 Total Adjusted EBITDA for reporting segments $ 62,092 $ 41,938 Unallocated net expenses (13,640 ) (8,132 ) Adjustments to Income (loss) before income tax provision (benefit) Depreciation and amortization (24,270 ) (24,141 ) Stock-based compensation costs (2,980 ) (685 ) Business transformation costs (1) — (163 ) Acquisition costs (2) — (565 ) Initial public offering costs — (1,978 ) Other costs ( 3 (1,467 ) (361 ) Interest expense (6,196 ) (19,759 ) Income (loss) before income taxes $ 13,539 $ (13,846 ) (1) Business transformation costs reflect consulting and other costs related to the transformation of the senior management team of $0.2 million for the three months ended December 31, 2019. (2) Acquisition costs reflect costs directly related to completed acquisitions $0.6 million for the three months ended December 31, 2019. (3) Other for legal expense of $0.5 million for the three months ended December 31, 2020 and costs related to an incentive plan and other ancillary expenses associated with the initial public offering of $1.0 million and $0.4 million for the three months ended December 31, 2020 and December 31, 2019, respectively.

Capital Stock

Capital Stock	3 Months Ended
	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
Capital Stock	11. 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 million shares of Class B common stock and up to 1 million shares of preferred stock, each par value $0.001 per share, in one or more series. 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. Holders of 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 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 5,532,037 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 September 15, 2020, the Company completed an offering of 28,750,000 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 3,750,000 additional shares of Class A common stock, at a public offering price of $33.25 per share. The shares were sold by the Selling Stockholders. The Company did not receive any of the proceeds from the sale of the shares by the Selling Stockholders. Immediately subsequent to the closing of the secondary offering, Class B common stockholders converted 33,068,863 shares of Class B common stock into Class A common stock.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	12. STOCK-BASED COMPENSATION The Company grants stock-based awards to attract, retain and motivate ke y Prior to the completion of the IPO, Profits Interests were issued through an LP Interest Agreement. The Profits Interests were, as part of the Corporate Conversion, converted into shares of common stock, restricted stock and stock options. The 2020 Omnibus Incentive Compensation Plan (“2020 Plan”), became effective as of June 11, 2020, the day of effectiveness of the registration statement filed in connection with the IPO. The 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 4,541,059 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 December 31, 2020 and 2019 was $2.9 million and $0.7 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 December 31, 2020 and 2019 was $0.5 million and $0.0 million, respectively. As of December 31, 2020, the Company had not yet recognized compensation cost on unvested stock-based awards of $33.6 million, with a weighted average remaining recognition period of 2.9 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 three months ende d December 4, 2020 Grant Date Risk-free interest rate 0.56 % Expected volatility 35.00 % Expected term (in years) 6.00 Expected dividend yield 0.00 % Stock Options The following table summarizes the performance-based stock option activity for the three month s 0 Number of Weighted Weighted Aggregate (in years) (in thousands) Outstanding at October 1, 2020 1,705,498 $ 23.00 — $ — Granted — — — — Exercised (78,617 ) 23.00 — 936 Cancelled/Forfeited — — — — Expired — — — — Outstanding at December 31, 2020 1,626,881 23.00 9.4 25,135 Vested and exercisable at December 31, 2020 1,626,881 23.00 9.4 25,135 The following table summarizes the service-based stock option activity for the three months ended December 31, 2020: Number of Weighted Weighted Aggregate (in years) (in thousands) Outstanding at October 1, 2020 3,382,947 $ 23.00 — $ — Granted 117,989 34.27 — — Exercised (24,162 ) 23.00 — 292 Cancelled/Forfeited (3,404 ) 23.00 — — Expired — — — — Outstanding at December 31, 2020 3,473,370 23.38 9.5 52,334 Vested and exercisable at December 31, 2020 1,004,631 23.00 9.5 15,522 Restricted Stock Awards A summary of the service-based restricted stock awards activity during the three months ended December 31, 2020 was as follows: Number Weighted Outstanding and unvested at October 1, 2020 1,485,611 $ 23.00 Granted — — Vested (160,809 ) 23.00 Forfeited (4,399 ) 23.00 Outstanding and unvested at December 31, 2020 1,320,403 23.00 Performance Restricted Stock Units Performance restricted stock units were g A summary of the performance-based restricted stock unit awards activity for the three months ended December 31, 2020 presented at target was as follows: Number of Weighted Average Outstanding and unvested at October 1, 2020 — $ — Granted 112,445 34.27 Vested — — Forfeited — — Outstanding and unvested at December 31, 2020 112,445 34.27 Restricted Stock Units A summary of the service-based restricted stock unit awards activity for the three months ended December 31, 2020 was as follow s Number of Weighted Average Outstanding and unvested at October 1, 2020 184,851 $ 23.00 Granted 173,734 34.51 Vested — — Forfeited (4,688 ) 23.00 Outstanding and unvested at December 31, 2020 353,897 28.70

Earnings Per Share

Earnings Per Share	3 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Share	13. EARNINGS PER SHARE The Company computes earnings per common share (“EPS”) under the two-class 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 December 31, 2020 2019 Numerator: Net income (loss) $ 10,183 $ (9,846 ) Net income (loss) attributable to common stockholders — basic and diluted $ 10,183 $ (9,846 ) Denominator: Weighted average shares of common stock Basic 153,226,378 108,162,741 Diluted 156,018,731 108,162,741 Net income (loss) attributable to common stockholders: Net income (loss) per share attributable to common stockholders Basic $ 0.07 $ (0.09 ) Diluted $ 0.07 $ (0.09 ) 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 December 31, 2020 2019 Restricted Stock Awards — — Stock Options 35,910 — Restricted Stock Units — —

Income Taxes

Income Taxes	3 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	14. INCOME TAXES The Company calculates the interim tax provision in accordance with the provisions of Accounting Standards Codification (“ASC”) 740-270, Income Taxes; Interim Reporting ASC-740-270-25-2. year-to-date The Company adopted ASU No. 2016-16 , Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory

Commitments And Contingencies

Commitments And Contingencies	3 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	15. COMMITMENTS AND CONTINGENCIES Lease Commitments The Company leases vehicles, machinery and a manufacturing facility under various capital leases. The Company also leases office equipment, vehicles and manufacturing and office facilities under various operating leases. In 2018, the Company entered into a lease agreement for its corporate headquarters in Chicago, IL. The Company was responsible for costs to build out the office space and spent approximately $3.4 million in improvements to meet the Company’s needs. Based on the lease agreement and the changes made to the office space the Company concluded that it was the “deemed owner” of the building (for accounting purposes only) during the construction period. The Company recorded the build out costs as an asset with a corresponding build-to-suit 840-40, Leases—Sale-Leaseback Transactions Future minimum annual payments under noncancelable leases with initial or remaining noncancelable lease terms in excess of one year as of December 31, 2020 were as follows (in thousands): Capital Financing Operating Remaining period of 2021 $ 1,278 $ 607 $ 2,177 2022 1,597 787 2,763 2023 1,206 806 2,563 2024 828 826 2,159 2025 616 846 1,719 Thereafter 2,191 3,823 3,397 Total payments $ 7,716 $ 7,695 $ 14,778 Less amount representing interest (3,687 ) Present value of minimum capital lease payments $ 4,029 Total rent expense was approximately $ 0.6 sublease s 1.1 Legal Proceedings In the normal course of the Company’s business, it is at times subject to pending and threatened 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. Loss Contingencies 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. As of December 31, 2020, there are various other worker’s compensation and personal injury claims that have been made against the Company. All such claims are being contested and the Company does not believe a loss is probable; therefore, no reserve has been recorded related to these matters. In addition, the Company carries insurance for these types of matters and is expecting to recover thereon. The Company is a party to various legal proceedings and claims, which arise in the ordinary course of business. As of December , , the Company determined that there was not at least a reasonable possibility that it had incurred a material loss, or a material loss in excess of a recorded accrual, with respect to such proceedings.

Condensed Financial Information

Condensed Financial Information of Registrant (Parent Company Only)	3 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Condensed Financial Information of Registrant (Parent Company Only)	16. 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) December 31, September 30, ASSETS: Non-current Investments in subsidiaries $ 1,319,103 $ 1,303,888 Total non-current 1,319,103 1,303,888 Total assets $ 1,319,103 $ 1,303,888 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 December 31, 2020 and at September 30, 2020, respectively — — Class A common stock, $ 0.00 155 155 Class B common stock, $0.001 par value; 100,000,000 shares authorized , 100 — — Additional paid-in 1,592,240 1,587,208 Accumulated deficit (273,292 ) (283,475 ) Total stockholders’ equity 1,319,103 1,303,888 Total liabilities and stockholders’ equity $ 1,319,103 $ 1,303,888 The AZEK Company Inc. (parent company only) Statements of Comprehensive Income (Loss) (In thousands of U.S. dollars) Three Months Ended December 31, 2020 20 19 Net income (loss) of subsidiaries $ 10,183 $ (9,846 ) Net income (loss) of subsidiaries $ 10,183 $ (9,846 ) Comprehensive income (loss) $ 10,183 $ (9,846 ) The AZEK Company Inc. did not have any cash as of December 31, 2020 or September 30, 2020, 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, S-X. 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 months ended December 31, 2020 and 2019. 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 7 to these Consolidated Financial Statements.

Subsequent Events

Subsequent Events	3 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	17. SUBSEQUENT EVENTS On Ja n certain of ose On February 2, 2021, the Company completed the repricing of its $467.7 million Term Loan Agreement. Under the amended Term Loan Agreement, the interest rate has been reduced by 125 basis points to LIBOR + 2.50% from LIBOR + 3.75%. Also, the LIBOR floor was reduced by 25 basis points to 0.75% from 1.00%. The maturity date for the Term Loan Agreement remains unchanged at May 5, 2024, and no changes were made to the outstanding principal, financial covenants or other terms of the agreement. The Company has evaluated subsequent events through the date the Consolidated Financial Statements were issued . other

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Dec. 31, 2020
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 and cash flows for the three months ended December 31, 2020 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 COVID-19 COVID-19 COVID-19 COVID-19 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 2020 Form 10-K. 10-K,
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 2020 Form 10-K
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 approximately $1.8 million and $2.1 million, respectively, for the three months ended December 31, 2020 and 2019.
Recently Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements Under the Jumpstart Our Business Startups (“JOBS”) Act, the Company qualifies as an emerging growth company (“EGC”) and as such, has elected not to opt out of the extended transition period for complying with new or revised accounting pronouncements. During the extended transition period, the Company is not subject to new or revised accounting standards applicable to public companies. The accounting pronouncements pending adoption below reflect effective dates for the Company as an EGC with the extended transition period. On October 1, 2019, the Company adopted ASU No. 2016-16, Income Taxes (Topic 740): Intra-Entity Transfer of Assets Other Than Inventory On October 1, 2020, the Company adopted ASU No. 2018-13, Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement, Fair Value Measurement Recently Issued Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-02, Leases (Topic 842), No. 2017-13, No. 2018-01, 2018-10 2018-11, No. 2018-20, No. 2019-01, No. 2019-10 No. 2020-05. right-of-use In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) No. 2019-05 2019-10 2019-11. off-balance In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-Use 350-40): internal-use In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740)—Simplifying the Accounting for Income Taxes In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848), Facilitation of the Effects of Reference Rate Reform on Financial Reporting

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Summary of Rebate Activity	The rebate activity was as follows (in thousands): Three Months Ended December 31, 2020 2019 Beginning balance $ 32,679 $ 24,858 Rebate expense 13,673 10,314 Rebate payments (7,533 ) (8,023 ) Ending balance $ 38,819 $ 27,149 The Company records deferred revenue when cash payments are received or due in advance of the Company’s performance.

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consisted of the following (in thousands): December 31, 2020 September 30, 2020 Raw materials $ 37,544 $ 33,850 Work in process 19,604 19,935 Finished goods 109,003 76,285 Total inventories $ 166,151 $ 130,070

Property, Plant and Equipment_2

Property, Plant and Equipment - Net (Tables)	3 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Summary of Property, Plant and Equipment - Net	Property, plant and equipment – net consisted of the following (in thousands): December 31, 2020 September 30, 2020 Land and improvements $ 2,758 $ 2,758 Buildings and improvements 73,080 71,059 Capital lease – building 2,021 2,021 Capital lease – manufacturing equipment 726 1,026 Capital lease – vehicles 4,356 3,782 Manufacturing equipment 324,287 306,036 Computer equipment 25,713 24,927 Furnitures and fixtures 5,809 5,689 Vehicles 465 465 Total property, plant and equipment 439,215 417,763 Construction in progress 61,748 54,412 500,963 472,175 Accumulated depreciation (221,780 ) (210,401 ) Total property, plant and equipment – net $ 279,183 $ 261,774

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Net (Tables)	3 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Finite-lived Intangible Assets	Finite-lived intangible assets consisted of the following (in thousands): December 31, 2020 Lives in Gross Accumulated Net Propriety knowledge 10 — $ 289,300 $ (200,578 ) $ 88,722 Trademarks 5 — 20 223,840 (128,340 ) 95,500 Customer relationships 15 — 146,670 (55,246 ) 91,424 Patents 10 7,000 (3,436 ) 3,564 Other intangible assets 3 — 15 4,076 (3,555 ) 521 Total intangible assets $ 670,886 $ (391,155 ) $ 279,731 September 30, 2020 Lives in Gross Accumulated Net Propriety knowledge 10 — 15 $ 289,300 $ (195,303 ) $ 93,997 Trademarks 5 — 20 223,840 (124,521 ) 99,319 Customer relationships 15 — 19 146,670 (52,119 ) 94,551 Patents 10 7,000 (3,182 ) 3,818 Other intangible assets 3 — 15 4,076 (3,387 ) 689 Total intangible assets $ 670,886 $ (378,512 ) $ 292,374

Composition of Certain Balanc_2

Composition of Certain Balance Sheet Accounts (Tables)	3 Months Ended
	Dec. 31, 2020
Composition of Certain Balance Sheet Accounts Disclosure [Abstract]
Summary of Allowance for Doubtful Accounts	Allowance for Doubtful Accounts Allowance for doubtful accounts consisted of the following (in thousands): December 31, 2020 September 30, 2020 Beginning balance $ 1,332 $ 904 Provision 6 512 Bad debt write-offs — (119 ) Acquisitions — 35 Ending balance $ 1,338 $ 1,332
Schedule of Accrued Expenses and Other Liabilities	Accrued Expenses and Other Liabilities Accrued expenses consisted of the following (in thousands): December 31, 2020 September 30, 2020 Employee related liabilities $ 18,555 $ 26,554 Freight 3,805 5,530 Professional fees 1,652 4,249 Marketing 2,859 3,343 Warranty 2,681 2,921 Construction in progress 2,054 1,303 Capital lease 1,047 969 Manufacturing related accrual s 2,776 1,664 Other 3,979 3,983 Total accrued expenses and other current liabilities $ 39,408 $ 50,516

Debt (Tables)

Debt (Tables)	3 Months Ended
	Dec. 31, 2020
Debt Instrument [Line Items]
Summary of Long-term Debt	Debt consisted of the following (in thousands): December 31, 2020 September 30, 2020 Term Loan Agreement due May 5, 2024 — LIBOR + 3.75% (4.75% and 4.75% at December 31, 2020 and September 30, 2020, respectively), (includes a discount of $472 and $507 at December 31, 2020 and September 30, 2020, respectively) $ 467,182 $ 467,147 Revolving Credit Facility through March 9, 2022 — LIBOR + 1.50% — — 2021 Senior Notes due October 1, 2021 — Fixed at 8% — — Total 467,182 467,147 Less unamortized deferred financing fees (3,874 ) (4,165 ) Less current portion — — Long-term debt — less current portion and unamortized financing fees $ 463,308 $ 462,982
Summary of Interest Expense	Interest expense consisted of the following (in thousands): Three Months Ended December 31, 2020 2019 Interest expense Term Loan Agreement $ 5,677 $ 12,143 2021 Senior Notes — 6,300 Revolving Credit Facility 165 153 Other 373 385 Amortization — — Debt issue costs Term Loan Agreement 291 495 2021 Senior Notes — 352 Revolving Credit Facility 141 89 Original issue discounts 35 60 Less capitalized interest (486 ) (218 ) Interest expense $ 6,196 $ 19,759
2021 Senior Notes [Member]
Debt Instrument [Line Items]
Summary of Debt Instrument Redemption	The 2021 Senior Notes were redeemable in whole or in part, at any time after October 1, 2016 at the following redemption prices, if redeemed during the 12-month 2016 106.0 % 2017 104.0 % 2018 102.0 % 2019 and thereafter 100.0 %

Product Warranties (Tables)

Product Warranties (Tables)	3 Months Ended
	Dec. 31, 2020
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): December 31, December 31 2019 Beginning balance $ 10,913 $ 11,133 Adjustments to reserve 723 1,372 Warranty claims payment (608 ) (950 ) Accretion — purchase accounting valuation 16 33 Ending balance 11,044 11,588 Current portion of accrued warranty (2,681 ) (3,001 ) Accrued warranty — less current portion $ 8,363 $ 8,587

Fair Value Of Financial Instr_2

Fair Value Of Financial Instruments (Tables)	3 Months Ended
	Dec. 31, 2020
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): December 31, 2020 September 30, 2020 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Term Loan Agreement due May 5, 2024 $ 467,182 $ 467,182 $ 467,147 $ 465,185

Segments (Tables)

Segments (Tables)	3 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Summary of Residential and Commercial Segment Reporting Information	The segment data below includes data for Residential and Commercial for the three months ended December 31 2020 and 2019 (in thousands). Three Months Ended December 31, 2020 2019 Net sales to customers Residential $ 185,640 $ 135,668 Commercial 26,638 30,375 Total $ 212,278 $ 166,043 Segment Adjusted EBITDA Residential $ 58,776 $ 38,915 Commercial 3,316 3,023 Total Adjusted EBITDA for reporting segments $ 62,092 $ 41,938 Unallocated net expenses (13,640 ) (8,132 ) Adjustments to Income (loss) before income tax provision (benefit) Depreciation and amortization (24,270 ) (24,141 ) Stock-based compensation costs (2,980 ) (685 ) Business transformation costs (1) — (163 ) Acquisition costs (2) — (565 ) Initial public offering costs — (1,978 ) Other costs ( 3 (1,467 ) (361 ) Interest expense (6,196 ) (19,759 ) Income (loss) before income taxes $ 13,539 $ (13,846 ) (1) Business transformation costs reflect consulting and other costs related to the transformation of the senior management team of $0.2 million for the three months ended December 31, 2019. (2) Acquisition costs reflect costs directly related to completed acquisitions $0.6 million for the three months ended December 31, 2019. (3) Other for legal expense of $0.5 million for the three months ended December 31, 2020 and costs related to an incentive plan and other ancillary expenses associated with the initial public offering of $1.0 million and $0.4 million for the three months ended December 31, 2020 and December 31, 2019, respectively.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Share-Based Compensation Stock Options Activity	The following table sets forth the significant assumptions used for the calculation of stock-based compensation expense for the three months ende d December 4, 2020 Grant Date Risk-free interest rate 0.56 % Expected volatility 35.00 % Expected term (in years) 6.00 Expected dividend yield 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 three month s 0 Number of Weighted Weighted Aggregate (in years) (in thousands) Outstanding at October 1, 2020 1,705,498 $ 23.00 — $ — Granted — — — — Exercised (78,617 ) 23.00 — 936 Cancelled/Forfeited — — — — Expired — — — — Outstanding at December 31, 2020 1,626,881 23.00 9.4 25,135 Vested and exercisable at December 31, 2020 1,626,881 23.00 9.4 25,135
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 three months ended December 31, 2020: Number of Weighted Weighted Aggregate (in years) (in thousands) Outstanding at October 1, 2020 3,382,947 $ 23.00 — $ — Granted 117,989 34.27 — — Exercised (24,162 ) 23.00 — 292 Cancelled/Forfeited (3,404 ) 23.00 — — Expired — — — — Outstanding at December 31, 2020 3,473,370 23.38 9.5 52,334 Vested and exercisable at December 31, 2020 1,004,631 23.00 9.5 15,522
Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Unvested Restricted Stock Units	A summary of the performance-based restricted stock unit awards activity for the three months ended December 31, 2020 presented at target was as follows: Number of Weighted Average Outstanding and unvested at October 1, 2020 — $ — Granted 112,445 34.27 Vested — — Forfeited — — Outstanding and unvested at December 31, 2020 112,445 34.27
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 three months ended December 31, 2020 was as follows: Number Weighted Outstanding and unvested at October 1, 2020 1,485,611 $ 23.00 Granted — — Vested (160,809 ) 23.00 Forfeited (4,399 ) 23.00 Outstanding and unvested at December 31, 2020 1,320,403 23.00
Schedule of Unvested Restricted Stock Units	A summary of the service-based restricted stock unit awards activity for the three months ended December 31, 2020 was as follow s Number of Weighted Average Outstanding and unvested at October 1, 2020 184,851 $ 23.00 Granted 173,734 34.51 Vested — — Forfeited (4,688 ) 23.00 Outstanding and unvested at December 31, 2020 353,897 28.70

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Dec. 31, 2020
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 December 31, 2020 2019 Numerator: Net income (loss) $ 10,183 $ (9,846 ) Net income (loss) attributable to common stockholders — basic and diluted $ 10,183 $ (9,846 ) Denominator: Weighted average shares of common stock Basic 153,226,378 108,162,741 Diluted 156,018,731 108,162,741 Net income (loss) attributable to common stockholders: Net income (loss) per share attributable to common stockholders Basic $ 0.07 $ (0.09 ) Diluted $ 0.07 $ (0.09 )
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 December 31, 2020 2019 Restricted Stock Awards — — Stock Options 35,910 — Restricted Stock Units — —

Commitments And Contingencies (

Commitments And Contingencies (Tables)	3 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Summary of Future Minimum Annual Payments Under Noncancelable Leases	Future minimum annual payments under noncancelable leases with initial or remaining noncancelable lease terms in excess of one year as of December 31, 2020 were as follows (in thousands): Capital Financing Operating Remaining period of 2021 $ 1,278 $ 607 $ 2,177 2022 1,597 787 2,763 2023 1,206 806 2,563 2024 828 826 2,159 2025 616 846 1,719 Thereafter 2,191 3,823 3,397 Total payments $ 7,716 $ 7,695 $ 14,778 Less amount representing interest (3,687 ) Present value of minimum capital lease payments $ 4,029

Condensed Financial Informati_2

Condensed Financial Information of Registrant (Parent Company Only) (Tables) - Parent Company [Member]	3 Months Ended
	Dec. 31, 2020
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) December 31, September 30, ASSETS: Non-current Investments in subsidiaries $ 1,319,103 $ 1,303,888 Total non-current 1,319,103 1,303,888 Total assets $ 1,319,103 $ 1,303,888 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 December 31, 2020 and at September 30, 2020, respectively — — Class A common stock, $ 0.00 155 155 Class B common stock, $0.001 par value; 100,000,000 shares authorized , 100 — — Additional paid-in 1,592,240 1,587,208 Accumulated deficit (273,292 ) (283,475 ) Total stockholders’ equity 1,319,103 1,303,888 Total liabilities and stockholders’ equity $ 1,319,103 $ 1,303,888
Schedule of Statements of Comprehensive Income (Loss)	The AZEK Company Inc. (parent company only) Statements of Comprehensive Income (Loss) (In thousands of U.S. dollars) Three Months Ended December 31, 2020 20 19 Net income (loss) of subsidiaries $ 10,183 $ (9,846 ) Net income (loss) of subsidiaries $ 10,183 $ (9,846 ) Comprehensive income (loss) $ 10,183 $ (9,846 )

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies - Additional Information (Detail) $ / shares in Units, $ in Thousands	Sep. 15, 2020$ / sharesshares	Jun. 16, 2020USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / shares	Dec. 31, 2019USD ($)	Sep. 30, 2020USD ($)$ / shares	Oct. 01, 2019USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]
Proceeds from issuance initial public offering		$ 819,700
Underwriting discounts and commissions payments		50,600
Estimated offering expenses payable		9,200
Research and development expenses			$ 1,800	$ 2,100
Retained earnings			$ (273,292)		$ (283,475)
Stock split conversion ratio			173
Revolving Credit Facility [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Revolving Credit Facility, outstanding amount		70,000	$ 4,400		$ 6,800
Revision of Prior Period, Adjustment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Retained earnings						$ 1,300
2020 Senior Notes [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Senior notes outstanding		350,000
Prepayment of senior notes		$ 337,700
IPO [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Shares issued during period | shares		38,237,500
Shares issued price | $ / shares		$ 23
Over-Allotment Option [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Shares issued during period | shares		4,987,500
Common Class A [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Common stock par or stated value per share | $ / shares			$ 0.001		$ 0.001
Common Class A [Member] | IPO [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Shares issued during period | shares		38,237,500
Common Class A [Member] | Over-Allotment Option [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Shares issued price | $ / shares	$ 33.25
Overallotment stock shares sold by shareholders during the period | shares	3,750,000
Common Class A [Member] | Secondary Offering Member [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Common stock par or stated value per share | $ / shares	$ 0.001
Stock shares sold by shareholders during the period | shares	28,750,000
Common Class B [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Common stock par or stated value per share | $ / shares			$ 0.001		$ 0.001
Conversion of Class B common stock into Class A common stock (in shares) | shares	33,068,863

Revenue - Additional Informatio

Revenue - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Accrued rebates	$ 35,754	$ 30,362	$ 24,900
Contra trade receivable	$ 3,100		$ 2,200

Revenue - Summary of Rebate Act

Revenue - Summary of Rebate Activity (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Beginning balance	$ 32,679	$ 24,858
Rebate expense	13,673	10,314
Rebate payments	(7,533)	(8,023)
Ending balance	$ 38,819	$ 27,149

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Inventory [Line Items]
Raw materials	$ 37,544	$ 33,850
Work in process	19,604	19,935
Finished goods	109,003	76,285
Total inventories	$ 166,151	$ 130,070

Property, Plant and Equipment_3

Property, Plant and Equipment - Net - Summary of Property, Plant and Equipment - Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Property, Plant and Equipment [Line Items]
Property Plant and Equipment Excluding Construction in Progress Gross	$ 439,215	$ 417,763
Property, Plant and Equipment, Gross	500,963	472,175
Accumulated depreciation	(221,780)	(210,401)
Total property, plant and equipment – net	279,183	261,774
Land and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	2,758	2,758
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	73,080	71,059
Capital Lease – Building [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	2,021	2,021
Capital Lease – Manufacturing Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	726	1,026
Capital Lease – Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	4,356	3,782
Manufacturing Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	324,287	306,036
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	25,713	24,927
Furnitures and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	5,809	5,689
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	465	465
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 61,748	$ 54,412

Property, Plant and Equipment_4

Property, Plant and Equipment - Net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2020
Property, Plant and Equipment [Line Items]
Finance lease right of use asset	$ 9,200		$ 9,200
Finance lease obligation	7,900		7,900
Depreciation	11,627	$ 10,283
Interest Capitalized	500	$ 200
Assets Under Capital Lease [Member]
Property, Plant and Equipment [Line Items]
Accumulated amortization under capital leases	4,200		4,000
Assets under Build to Suit lease [Member]
Property, Plant and Equipment [Line Items]
Accumulated amortization leased assets	$ 600		$ 500

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2020
Goodwill [Line Items]
Goodwill	$ 951,390		$ 951,390
Accumulated goodwill impairments	32,200
Amortization expense	$ 12,643	$ 13,858
Acquired finite lived intangible assets weighted average useful life	12 years 9 months 18 days
Residential Segment [Member]
Goodwill [Line Items]
Goodwill	$ 911,000		911,000
Commercial Segment [Member]
Goodwill [Line Items]
Goodwill	$ 40,400		$ 40,400

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Net - Summary of Finite-Lived Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 670,886	$ 670,886
Accumulated Amortization	(391,155)	(378,512)
Total	279,731	292,374
Propriety knowledge [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	289,300	289,300
Accumulated Amortization	(200,578)	(195,303)
Total	$ 88,722	$ 93,997
Propriety knowledge [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Lives in Years	10 years	10 years
Propriety knowledge [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Lives in Years	15 years	15 years
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 223,840	$ 223,840
Accumulated Amortization	(128,340)	(124,521)
Total	$ 95,500	$ 99,319
Trademarks [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Lives in Years	5 years	5 years
Trademarks [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Lives in Years	20 years	20 years
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 146,670	$ 146,670
Accumulated Amortization	(55,246)	(52,119)
Total	$ 91,424	$ 94,551
Customer relationships [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Lives in Years	15 years	15 years
Customer relationships [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Lives in Years	19 years	19 years
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Lives in Years	10 years	10 years
Gross Carrying Value	$ 7,000	$ 7,000
Accumulated Amortization	(3,436)	(3,182)
Total	3,564	3,818
Other intangible assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	4,076	4,076
Accumulated Amortization	(3,555)	(3,387)
Total	$ 521	$ 689
Other intangible assets [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Lives in Years	3 years	3 years
Other intangible assets [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Lives in Years	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	12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020
Allowance for Credit Loss [Abstract]
Beginning balance	$ 1,332	$ 904
Provision	6	512
Bad debt write-offs		(119)
Acquisition		35
Ending balance	$ 1,338	$ 1,332

Composition of Certain Balanc_4

Composition of Certain Balance Sheet Accounts - Summary of Accrued Expenses and Other Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Accrued Liabilities and Other Liabilities [Abstract]
Employee related liabilities	$ 18,555	$ 26,554
Freight	3,805	5,530
Professional fees	1,652	4,249
Marketing	2,859	3,343
Warranty	2,681	2,921
Construction in progress	2,054	1,303
Capital lease	1,047	969
Manufacturing related accruals	2,776	1,664
Other	3,979	3,983
Total accrued expenses and other current liabilities	$ 39,408	$ 50,516

Debt - Summary of Long-Term Deb

Debt - Summary of Long-Term Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 467,182	$ 467,147
Less: unamortized deferred financing fees	(3,874)	(4,165)
Less: current portion
Long-term debt — less current portion and unamortized financing fees	463,308	462,982
Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	467,182	467,147
2021 Senior Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross

Debt - Summary of Long-Term D_2

Debt - Summary of Long-Term Debt (Detail) (Parenthetical) - USD ($) $ in Thousands	Mar. 09, 2017	Sep. 30, 2013	Dec. 31, 2020	Sep. 30, 2020
Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument maturity date			May 5, 2024
Debt instrument, description of variable rate basis			LIBOR + 3.75%
Debt instrument, basis spread on variable rate			3.75%
Debt instrument rate			4.75%	4.75%
Debt instrument unamortized discount			$ 472	$ 507
2021 Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument maturity date		Oct. 1, 2021	Oct. 1, 2021
Debt instrument fixed interest rate		8.00%	8.00%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument maturity date	Mar. 9, 2022		Mar. 9, 2022
Debt instrument, description of variable rate basis			LIBOR + 1.50%
Debt instrument, basis spread on variable rate			1.50%

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($) $ in Thousands	May 07, 2020	Mar. 09, 2017	Sep. 30, 2013	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2020	Jun. 16, 2020
Debt Instrument [Line Items]
Deferred financing cost				$ 3,874		$ 4,165
Long-Term Debt, Maturity, Year Five				$ 467,700
CPG International LLC [Member]
Debt Instrument [Line Items]
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.
Senor Notes Due Two Thousand And Twenty One [Member] | CPG International LLC [Member] | Wilmington Trust National Association [Member]
Debt Instrument [Line Items]
Debt instrument maturity date			Oct. 1, 2021
Debt instrument interest rate			8.00%
Maximum [Member] | CPG International LLC [Member]
Debt Instrument [Line Items]
Minimum fixed charge coverage ratio				100
Minimum [Member] | CPG International LLC [Member]
Debt Instrument [Line Items]
Minimum fixed charge coverage ratio				100
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument maturity date		Mar. 9, 2022		Mar. 9, 2022
Aggregate maximum borrowing capacity		$ 150,000
Outstanding borrowings capacity				$ 4,400		6,800	$ 70,000
Outstanding letters of credit held				700		800
Option to increase the commitments				$ 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.
Debt instrument, description of variable rate basis				LIBOR + 1.50%
Line of credit facility, commitment fee amount				$ 100	$ 100
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.
Revolving Credit Facility [Member] | CPG International LLC [Member]
Debt Instrument [Line Items]
Available borrowing capacity				$ 143,300
Revolving Credit Facility [Member] | ABR Borrowings [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 50 to 100 basis points, based on average historical availability, or (ii) for Eurocurrency borrowings, adjusted LIBOR plus a spread of 150 to 200 basis points, based on average historical availability.
Revolving Credit Facility [Member] | ABR Borrowings [Member] | Fed Funds Effective Rate Overnight Index Swap Rate [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis				Federal Funds Rate plus 50 basis points
Revolving Credit Facility [Member] | ABR Borrowings [Member] | London Interbank Offered Rate (LIBOR) [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 50 to 100 basis points
Revolving Credit Facility [Member] | ABR Borrowings [Member] | Prime Rate [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis				prime rate
Revolving Credit Facility [Member] | Eurocurrency Borrowings [Member]
Debt Instrument [Line Items]
Debt instrument interest rate description				for Eurocurrency borrowings, adjusted LIBOR plus a spread of 150 to 200 basis points, based on average historical availability
Revolving Credit Facility [Member] | Eurocurrency Borrowings [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis				LIBOR plus a spread of 150 to 200 basis points
Revolving Credit Facility [Member] | FILO Loans [Member]
Debt Instrument [Line Items]
Aggregate maximum borrowing capacity		$ 8,500
Amended Agreement For Term Loan [Member] | CPG International LLC [Member] | Wilmington Trust National Association [Member]
Debt Instrument [Line Items]
Debt instrument maturity date				May 5, 2024
Deferred financing cost				$ 3,900		$ 4,200
Prepay of outstanding principal of term loan agreement				$ 337,700
Percentage of principal amount to be repaid by way of instalments				0.25253%
Term loan frequency of instalment payment				quarterly installments
2021 Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument face amount			$ 315,000
Debt instrument maturity date			Oct. 1, 2021	Oct. 1, 2021
Debt instrument interest rate			8.00%	8.00%
Debt instrument, repurchase amount	$ 315,000
Debt Instrument, Repurchase Date	Jun. 8, 2020

Debt - Disclosure of Debt Instr

Debt - Disclosure of Debt Instrument Redemption (Detail) - 2021 Senior Notes [Member]	12 Months Ended
	Sep. 30, 2017
Debt Instrument, Redemption, Period One [Member]
Debt Instrument, Redemption [Line Items]
Debt Instrument, Redemption Price, Percentage	106.00%
Debt Instrument, Redemption, Period Two [Member]
Debt Instrument, Redemption [Line Items]
Debt Instrument, Redemption Price, Percentage	104.00%
Debt Instrument, Redemption, Period Three [Member]
Debt Instrument, Redemption [Line Items]
Debt Instrument, Redemption Price, Percentage	102.00%
Debt Instrument, Redemption, Period Four [Member]
Debt Instrument, Redemption [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%

Debt - Summary of Interest Expe

Debt - Summary of Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Interest expense
Other	$ 373	$ 385
Debt issuance costs
Original issue discounts	35	60
Less capitalized interest	(486)	(218)
Interest expense	6,196	19,759
Term Loan [Member]
Interest expense
Interest expense, debt	5,677	12,143
Debt issuance costs
Amortization of debt issuance costs	291	495
2021 Senior Notes [Member]
Interest expense
Interest expense, debt		6,300
Debt issuance costs
Amortization of debt issuance costs		352
Revolving Credit Facility [Member]
Interest expense
Interest expense, debt	165	153
Debt issuance costs
Amortization of debt issuance costs	$ 141	$ 89

Product Warranties - Additional

Product Warranties - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2020	Sep. 30, 2020
Product Warranty Liability [Line Items]
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.
Other Current Assets [Member]
Product Warranty Liability [Line Items]
Product warranty classified as current	$ 1.8	$ 1.8

Product Warranties - Summary of

Product Warranties - Summary of Warranty Reserve Activity (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Product Warranty Liability [Line Items]
Beginning balance	$ 10,913	$ 11,133
Adjustments to reserve	723	1,372
Warranty claims payment	(608)	(950)
Accretion — purchase accounting valuation	16	33
Ending balance	11,044	11,588
Current portion of accrued warranty	(2,681)	(3,001)
Accrued warranty — less current portion	$ 8,363	$ 8,587

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) - Fair Value, Inputs, Level 2 [Member] - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Carrying Value [Member]
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Term Loan Agreement due May 5, 2024	$ 467,182	$ 467,147
Estimated Fair Value [Member]
Schedule of carrying values and the estimated fair values of the debt financial instruments [Line Items]
Term Loan Agreement due May 5, 2024	$ 467,182	$ 465,185

Fair Value Of Financial Instr_4

Fair Value Of Financial Instruments - Additional Information (Detail) - Fair Value, Inputs, Level 3 [Member] - Fair Value, Recurring [Member] $ in Thousands	Dec. 31, 2020USD ($)
Assets measured at fair value on a recurring basis	$ 0
Liabilities measured at fair value on a recurring basis	$ 0

Segment - Additional Informatio

Segment - Additional Information (Detail)	3 Months Ended
	Dec. 31, 2020Segment
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
	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net sales to customers	$ 212,278	$ 166,043
Segment Adjusted EBITDA
Total Adjusted EBITDA for reporting segments	62,092	41,938
Unallocated net expenses	(13,640)	(8,132)
Adjustments to Income (loss) before income tax provision (benefit)
Depreciation and amortization	(24,270)	(24,141)
Stock-based compensation costs	(2,980)	(685)
Business transformation costs		(163)
Acquisition costs		(565)
Initial public offering costs		(1,978)
Other costs	(1,467)	(361)
Interest expense	(6,196)	(19,759)
Income (loss) before income taxes	13,539	(13,846)
Residential [Member]
Segment Reporting Information [Line Items]
Net sales to customers	185,640	135,668
Segment Adjusted EBITDA
Total Adjusted EBITDA for reporting segments	58,776	38,915
Commercial [Member]
Segment Reporting Information [Line Items]
Net sales to customers	26,638	30,375
Segment Adjusted EBITDA
Total Adjusted EBITDA for reporting segments	$ 3,316	$ 3,023

Segments - Summary of Residen_2

Segments - Summary of Residential and Commercial Segment Reporting Information (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Business Transformation Costs [Line Items]
Business acquisition acquisition costs completed acquistions		$ 0.6
Legal expenses	$ 0.5
IPO [Member]
Business Transformation Costs [Line Items]
Costs related to an incentive plan	$ 1	0.4
Business Transformation Costs [Member]
Business Transformation Costs [Line Items]
Compensation costs for transformation		$ 0.2

Capital Stock - Additional Info

Capital Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Sep. 15, 2020	Jun. 16, 2020	Dec. 31, 2020	Sep. 30, 2020
Class of Stock [Line Items]
Proceeds from initial public offering, net of related costs		$ 819.7
Underwriting commision and discounts		50.6
Estimated offering expenses payable		$ 9.2
Preferred stock, shares authorized			1,000,000	1,000,000
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.
Preferred stock par or stated value per share			$ 0.001	$ 0.001
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 or stated 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 Profit Interests [Member]
Class of Stock [Line Items]
Common stock member interests converted			2,703,243
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 B [Member]
Class of Stock [Line Items]
Common stock, shares authorized			100,000,000	100,000,000
Common stock par or stated value per share			$ 0.001	$ 0.001
Common stock member interests converted	33,068,863
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			5,532,037
IPO [Member]
Class of Stock [Line Items]
Shares issued during period		38,237,500
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]
Overallotment stock shares sold by shareholders during the period	3,750,000
Shares issued price	$ 33.25
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]
Stock shares sold by shareholders during the period	28,750,000
Common stock par or stated value per share	$ 0.001

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expenses	$ 2,980	$ 685
Income tax benefit stock based compensation expenses	500	0
Unvested stock compensation not recognised	$ 33,600
Unvested stock awards weighted average remaining period of recognition	2 years 10 months 24 days
Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expenses	$ 2,900	$ 700
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
Common stock shares reserved for future issuance	4,541,059
Stock based compensation period of expiry of stock options	10 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Restricted Stock Awards Granted (Detail)	3 Months Ended
	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.56%
Expected volatility	35.00%
Expected term (in years)	6 years
Expected dividend yield	0.00%

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Option Activities (Detail) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Option, Outstanding | shares	1,705,498
Number of Option, Granted | shares
Number of Option, Exercised | shares	(78,617)
Number of Option, Cancelled/Forfeited | shares
Number of Option, Expired | shares
Number of Option, Outstanding | shares	1,626,881
Number of Option, Vested and exercisable | shares	1,626,881
Weighted Average Exercise Price Per Share, Outstanding | $ / shares	$ 23
Weighted Average Exercise Price Per Share, Granted | $ / shares	0
Weighted Average Exercise Price Per Share, Exercised | $ / shares	23
Weighted Average Exercise Price Per Share, Cancelled/Forfeited | $ / shares	0
Weighted Average Exercise Price Per Share, Expired | $ / shares	0
Weighted Average Exercise Price Per Share, Outstanding | $ / shares	23
Weighted Average Exercise Price Per Share, Vested and exercisable | $ / shares	$ 23
Weighted Average Remaining Contract Term, Outstanding	9 years 4 months 24 days
Weighted Average Remaining Contract Term, Vested and exercisable	9 years 4 months 24 days
Weighted Average Intrinsic Value, Exercised | $	$ 936
Weighted Average Intrinsic Value, Outstanding | $	25,135
Weighted Average Intrinsic Value, Vested and exercisable | $	$ 25,135
Service Based Stock Option Activity [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Option, Outstanding | shares	3,382,947
Number of Option, Granted | shares	117,989
Number of Option, Exercised | shares	(24,162)
Number of Option, Cancelled/Forfeited | shares	3,404
Number of Option, Expired | shares
Number of Option, Outstanding | shares	3,473,370
Number of Option, Vested and exercisable | shares	1,004,631
Weighted Average Exercise Price Per Share, Outstanding | $ / shares	$ 23
Weighted Average Exercise Price Per Share, Granted | $ / shares	34.27
Weighted Average Exercise Price Per Share, Exercised | $ / shares	23
Weighted Average Exercise Price Per Share, Cancelled/Forfeited | $ / shares	23
Weighted Average Exercise Price Per Share, Expired | $ / shares
Weighted Average Exercise Price Per Share, Outstanding | $ / shares	23.38
Weighted Average Exercise Price Per Share, Vested and exercisable | $ / shares	$ 23
Weighted Average Remaining Contract Term, Outstanding	9 years 6 months
Weighted Average Remaining Contract Term, Vested and exercisable	9 years 6 months
Weighted Average Intrinsic Value, Exercised | $	$ 292
Weighted Average Intrinsic Value, Outstanding | $	52,334
Weighted Average Intrinsic Value, Vested and exercisable | $	$ 15,522

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Stock Awards Activity Other Than Options (Detail)	3 Months Ended
	Dec. 31, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding and unvested | shares	184,851
Number of Shares, Granted | shares	173,734
Number of Shares, Vested | shares
Number of Shares, Forfeited | shares	4,688
Number of Shares, Outstanding and unvested | shares	353,897
Weighted Average Grant Date Fair Value, Outstanding and unvested	$ 23
Weighted Average Grant Date Fair Value, Granted	34.51
Weighted Average Grant Date Fair Value, Vested
Weighted Average Grant Date Fair Value, Outstanding and unvested	$ 28.70
Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding and unvested | shares
Number of Shares, Granted | shares	112,445
Number of Shares, Outstanding and unvested | shares	112,445
Weighted Average Grant Date Fair Value, Outstanding and unvested
Weighted Average Grant Date Fair Value, Granted	34.27
Weighted Average Grant Date Fair Value, Vested
Weighted Average Grant Date Fair Value, Forfeited
Weighted Average Grant Date Fair Value, Outstanding and unvested	$ 34.27
Service Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding and unvested | shares	1,485,611
Number of Shares, Granted | shares
Number of Shares, Vested | shares	160,809
Number of Shares, Forfeited | shares	4,399
Number of Shares, Outstanding and unvested | shares	1,320,403
Weighted Average Grant Date Fair Value, Outstanding and unvested	$ 23
Weighted Average Grant Date Fair Value, Granted
Weighted Average Grant Date Fair Value, Vested	23
Weighted Average Grant Date Fair Value, Forfeited	23
Weighted Average Grant Date Fair Value, Outstanding and unvested	$ 23

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Restricted Stock Unit Awards Activity (Detail)	3 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Number of Shares, Outstanding and unvested	184,851
Number of Shares, Granted	173,734
Number of Shares, Vested
Number of Shares, Forfeited	4,688
Number of Shares, Outstanding and unvested	353,897
Weighted Average Grant Date Fair Value, Outstanding and unvested | $ / shares	$ 23
Weighted Average Grant Date Fair Value, Granted | $ / shares	34.51
Weighted Average Grant Date Fair Value, Vested | $ / shares
Weighted Average Grant Date Fair Value, Forfeited | $	$ 23
Weighted Average Grant Date Fair Value, Outstanding and unvested | $ / shares	$ 28.70

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
	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net income (loss)	$ 10,183	$ (9,846)
Net income (loss) attributable to common stockholders - basic and diluted	$ 10,183	$ (9,846)
Denominator:
Basic	153,226,378	108,162,741
Diluted	156,018,731	108,162,741
Basic	$ 0.07	$ (0.09)
Diluted	$ 0.07	$ (0.09)

Earnings Per Share - Summary _2

Earnings Per Share - Summary of Antidilutive Securities Excluded From Computation of Earnings Per Share (Detail)	3 Months Ended
	Dec. 31, 2020shares
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	35,910
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

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail)	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Effective income tax reconcilation percentage	24.80%	28.90%

Commitments And Contingencies -

Commitments And Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2019
Loss Contingencies [Line Items]
Finance lease right of use asset	$ 9.2
Finance lease incremental borrowing rate	8.40%
Lease rental expenses	$ 0.6	$ 0.3
Future minimum sublease income receivable	$ 1.1
Workmen Compensation [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Estimate Of Possible Loss				$ 0.4
Workmen Compensation [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Estimate Of Possible Loss				$ 0.5
Leasehold Improvements [Member]
Loss Contingencies [Line Items]
Lease improvements expenditure incurred			$ 3.4

Commitments And Contingencies_2

Commitments And Contingencies - Summary of Future Minimum Annual Payments Under Noncancelable Leases (Detail) $ in Thousands	Dec. 31, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
Capital Remaining period of 2021	$ 1,278
2022	1,597
2023	1,206
2024	828
2025	616
Thereafter	2,191
Total payments	7,716
Less amount representing interest	(3,687)
Present value of minimum capital lease payments	4,029
Finance Remaining period of 2021	607
2022	787
2023	806
2024	826
2025	846
Thereafter	3,823
Total payments	7,695
Operating Remaining period of 2021	2,177
2022	2,763
2023	2,563
2024	2,159
2025	1,719
Thereafter	3,397
Total payments	$ 14,778

Condensed Financial Informati_3

Condensed Financial Information of Registrant (Parent Company Only) - Schedule of Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Non-current assets:
Total assets	$ 1,940,904	$ 1,931,856
LIABILITIES AND STOCKHOLDERS' EQUITY:
Total liabilities	621,801	627,968
Stockholders' equity:
Preferred stock, $0.001 par value; 1,000,000 shares authorized and no shares issued and outstanding at December 31, 2020 and at September 30, 2020, respectively
Additional paid-in capital	1,592,240	1,587,208
Accumulated deficit	(273,292)	(283,475)
Total stockholders' equity	1,319,103	1,303,888	$ 479,996	$ 490,023
Total liabilities and stockholders' equity	1,940,904	1,931,856
Parent Company [Member]
Non-current assets:
Investments in subsidiaries	1,319,103	1,303,888
Total non-current assets	1,319,103	1,303,888
Total assets	1,319,103	1,303,888
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 December 31, 2020 and at September 30, 2020, respectively
Additional paid-in capital	1,592,240	1,587,208
Accumulated deficit	(273,292)	(283,475)
Total stockholders' equity	1,319,103	1,303,888
Total liabilities and stockholders' equity	1,319,103	1,303,888
Common Class A [Member]
Stockholders' equity:
Common stock value	155	155
Total stockholders' equity	155	155	75	75
Common Class A [Member] | Parent Company [Member]
Stockholders' equity:
Common stock value	155	155
Common Class B [Member]
Stockholders' equity:
Common stock value
Total stockholders' equity			$ 33	$ 33
Common Class B [Member] | Parent Company [Member]
Stockholders' equity:
Common stock value

Condensed Financial Informati_4

Condensed Financial Information of Registrant (Parent Company Only) - Schedule of Balance Sheets (Parenthetical) (Detail) - $ / shares	Dec. 31, 2020	Sep. 30, 2020
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 or stated value per share	$ 0.001	$ 0.001
Common stock, shares authorized	1,100,000,000	1,100,000,000
Common stock, shares issued	154,735,617	154,637,240
Common stock, shares outstanding	154,735,617	154,637,240
Common Class B [Member]
Common stock par or stated 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 or stated value per share	$ 0.001	$ 0.001
Common stock, shares authorized	1,100,000,000	1,100,000,000
Common stock, shares issued	154,735,617	154,637,240
Common stock, shares outstanding	154,735,617	154,637,240
Parent Company [Member] | Common Class B [Member]
Common stock par or stated 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
	Dec. 31, 2020	Dec. 31, 2019
Condensed Statement of Income Captions [Line Items]
Comprehensive income (loss)	$ 10,183	$ (9,846)
Parent Company [Member]
Condensed Statement of Income Captions [Line Items]
Net income (loss) of subsidiaries	10,183	(9,846)
Net income (loss) of subsidiaries	10,183	(9,846)
Comprehensive income (loss)	$ 10,183	$ (9,846)

Condensed Financial Informati_6

Condensed Financial Information of Registrant (Parent Company Only) - Additional Information (Detail)	Dec. 31, 2020
Parent Company [Member]
Condensed Statement of Income Captions [Line Items]
Minimum threshold percentage of restricted net assets	25.00%

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Feb. 02, 2021	Jan. 26, 2021	Dec. 31, 2020
Subsequent Event [Line Items]
Term loan			$ 467.7
Subsequent Event [Member]
Subsequent Event [Line Items]
Stock shares sold by shareholders during the period		20,000,000
Common stock par or stated value per share		$ 0.001
Sale of stock, price per share		$ 40
Estimated offering expenses		$ 1.8
Subsequent Event [Member] | Maximum [Member]
Subsequent Event [Line Items]
Overallotment stock shares sold by shareholders during the period		3,000,000
Subsequent Event [Member] | Term Loan Agreement [Member]
Subsequent Event [Line Items]
Term loan	$ 467.7
Debt instrument maturity date	May 5, 2024
Subsequent Event [Member] | Term Loan Agreement [Member] | Maximum [Member]
Subsequent Event [Line Items]
LIBOR, floor interest rate	1.00%
Debt instrument, description of variable rate basis	LIBOR + 3.75
Subsequent Event [Member] | Term Loan Agreement [Member] | Minimum [Member]
Subsequent Event [Line Items]
LIBOR, floor interest rate	0.75%
Debt instrument, description of variable rate basis	LIBOR + 2.50