Initial Statement of Beneficial Ownership (Form 3)

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Lauer Zachary C. 2. Date of Event Requiring Statement (Month/Day/Year) 04/28/2026 3. Issuer Name and Ticker or Trading Symbol TREX CO INC [TREX] (Last) (First) (Middle) 2500 TREX WAY, C/O TREX COMPANY, INC. 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) SVP, Chief Operations Officer 5. If Amendment, Date Original Filed (Month/Day/Year) (Street) WINCHESTER, VA 22601 6. Individual or Joint/Group Filing (Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 28,187(1) D

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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Appreciation Right	02/19/2023(2)	02/19/2030	Common Stock	2,166	$50.83	D
Stock Appreciation Right	02/17/2024(3)	02/17/2031	Common Stock	810	$104.56	D
Stock Appreciation Right	03/01/2025(4)	02/23/2032	Common Stock	1,338	$82.01	D
Stock Appreciation Right	03/01/2026(5)	02/14/2033	Common Stock	2,152	$56.8	D
Stock Appreciation Right	03/01/2027(6)	02/19/2034	Common Stock	1,522	$90.86	D
Stock Appreciation Right	03/01/2028(7)	02/17/2035	Common Stock	2,481	$67.33	D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Lauer Zachary C. 2500 TREX WAY C/O TREX COMPANY, INC. WINCHESTER, VA 22601			SVP, Chief Operations Officer

Signatures

/s/ Amy M. Fernandez by power of attorney		05/06/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Includes 3,848 time-based restricted stock units that vest March 1, 2027; 3,264 time-based restricted stock units that vest March 1, 2028; 2,304 time-based restricted stock units that vest March 1, 2029; a target number of 4,509 performance-based restricted stock units that vest on March 1, 2027; a target number of 3,675 performance-based restricted stock units that vest on March 1, 2028; and a target number of 2,304 performance-based restricted stock units that vest on March 1, 2029. The number of performance-based restricted stock units set forth above is the target number of shares. The number of shares that will actually vest will be based upon performance against certain financial goals for the Company and will range from 0% to 200% of the target number of shares.
(2)	This stock appreciation right became exercisable in three equal installments that occurred on February 19, 2021, February 19, 2022, and February 19, 2023.
(3)	This stock appreciation right became exercisable in three equal installments that occurred on February 17, 2022, February 17, 2023, and February 17, 2024.
(4)	This stock appreciation right became exercisable in three equal installments that occurred on March 1, 2023, March 1, 2024, and March 1, 2025.
(5)	This stock appreciation right became exercisable in three equal installments that occurred on March 1, 2024, March 1, 2025, and March 1, 2026.
(6)	This stock appreciation right vests in three equal annual installments; the first and second installments became exercisable on March 1, 2025 and March 1, 2026, respectively, and the third installment will become exercisable on March 1, 2027.
(7)	This stock appreciation right vests in three equal annual installments; the first installment became exercisable on March 1, 2026, and the second and third installments will become exercisable on March 1, 2027 and March 1, 2028, respectively.

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