SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Schemm Dennis Charles (Last) (First) (Middle) 42764 CEDAR RIDGE BLVD (Street) CHANTILLY VA 20152 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol TREX CO INC [ TREX ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) SVP, Chief Financial Officer
	3. Date of Earliest Transaction (Month/Day/Year) 02/14/2023
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/14/2023		A(1)		6,076	A	$56.8	23,431(2)	D
Common Stock	02/14/2023		A(3)		8,680	A	$56.8	32,111	D
Common Stock	02/14/2023		A(4)		1,494	A	$56.8	33,605	D
Common Stock	02/14/2023		F(5)		1,890	D	$56.8	31,715	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Appreciation Right	$56.8	02/14/2023		A(6)		5,439		03/01/2024	02/14/2033	Common Stock	5,439	$56.8	5,439	D

Explanation of Responses:

1. This restricted stock unit vests over a three-year period in three equal annual installments occurring March 1,2024, March 1, 2025 and March 1, 2026.

2. Includes 189 shares acquired under the Company ESPP in March 2022

3. This restricted stock unit award is performance-based, and vests over a three-year period in three equal installments occurring March 1,2024, March 1, 2025 and March 1, 2026. The number of shares set forth above is the target number of shares. The number of shares that will actually vest each year 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.

4. Represents net share difference between target performance-based shares and actual vested shares, based upon actual performance for the Company.

5. 1,890 shares are being surrendered as allowed by the Company's 2014 Stock Incentive Plan to cover payment of taxes currently due on previously granted restricted stock units.

6. The stock appreciation right becomes exercisable in three equal installments occurring March 1,2024, March 1, 2025 and March 1, 2026.

	/s/ William R. Gupp by power of attorney	02/16/2023
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (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).
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