foam and several complementary installed products, continued to be difficult to source near volume and pricing levels secured in prior periods. Third quarter gross profit was reduced by an estimated $2.0 million due to supply chain disruptions that occurred during the quarter, which reduced gross profit margin by approximately 40 basis points and had the same impact to operating profit margin and adjusted EBITDA* margin.
Selling and administrative expense, as a percent of net revenue, was 18.1% compared to 18.8% in the prior year quarter, the most favorable quarterly result since becoming a public company. Adjusted selling and administrative expense*, as a percent of net revenue, was 17.5% compared to 18.0% in the prior year quarter.
Net income was $34.9 million, or $1.18 per diluted share, compared to $28.1 million, or $0.95 per diluted share in the prior year quarter. Adjusted net income* was $44.0 million, or $1.49 per diluted share, compared to $35.9 million, or $1.21 per diluted share in the prior year quarter. Adjusted net income accounts for the impact of non-core items in both periods, including COVID-19 expenses and an addback for non-cash amortization expense related to acquisitions.
Adjusted EBITDA* was $78.1 million, an 18.0% increase from $66.2 million in the prior year quarter, largely due to strong residential sales, revenue from key commercial acquisitions, and leverage on selling and administrative expenses compared to the prior year quarter.
2021 Fourth Quarter Regular Cash Dividend
IBP’s Board of Directors has approved the Company’s quarterly cash dividend of $0.30 per share, payable on December 31, 2021, to stockholders of record on December 15, 2021.
Conference Call and Webcast
The Company will host a conference call and webcast on November 4, 2021 at 10:00 a.m. Eastern Time to discuss these results. To participate in the call, please dial 1-877-407-0792 (domestic) or 1-201-689-8263 (international). The live webcast will be available at www.installedbuildingproducts.com in the investor relations section. A replay of the conference call will be available through December 4, 2021, by dialing 1-844-512-2921 (domestic) or 1-412-317-6671 (international) and entering the passcode 13723357.
About Installed Building Products
Installed Building Products, Inc. is one of the nation’s largest new residential insulation installers and is a diversified installer of complementary building products, including waterproofing, fire-stopping, fireproofing, garage doors, rain gutters, window blinds, shower doors, closet shelving and mirrors and other products for residential and commercial builders located in the continental United States. The Company manages all aspects of the installation process for its customers, from direct purchase and receipt of materials from national manufacturers to its timely supply of materials to job sites and quality installation. The Company offers its portfolio of services for new and existing single-family and multi-family residential and commercial building projects from its national network of over 190 branch locations.
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