Exhibit 32.1

Certification of Chief Executive Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section

906 of the Sarbanes-Oxley Act of 2002

In connection with the Quarterly Report on Form 10-Q/A of The AZEK Company Inc., (the “Company”) for the period ended December 31, 2023 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that:

(1)The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

(2)The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: June 14, 2024	By:	/s/ Jesse Singh
		Jesse Singh
		Chief Executive Officer (Principal Executive Officer)