TREX CO INC — Director's Dealing 2014

May 8, 2014

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TREX CO INC (TREX)
CIK: 0001069878
Period of Report: 2014-05-07

Reporting Person: Gupp William R. (CAO, Gen. Counsel & Secretary)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2014-05-07	Common Stock	M	3000	$24.17	Acquired	36473	Direct
2014-05-07	Common Stock	M	2306	$25.37	Acquired	38779	Direct
2014-05-07	Common Stock	D	1910	$68.59	Disposed	36869	Direct
2014-05-07	Common Stock	F	1446	$68.59	Disposed	35423	Direct
2014-05-07	Common Stock	S	300	$70.01	Disposed	35123	Direct
2014-05-07	Common Stock	S	100	$70.02	Disposed	35023	Direct
2014-05-07	Common Stock	S	300	$70.04	Disposed	34723	Direct
2014-05-07	Common Stock	S	100	$70.05	Disposed	34623	Direct
2014-05-07	Common Stock	S	100	$70.06	Disposed	34523	Direct
2014-05-07	Common Stock	S	100	$70.09	Disposed	34423	Direct
2014-05-07	Common Stock	S	100	$70.11	Disposed	34323	Direct
2014-05-07	Common Stock	S	500	$70.85	Disposed	33823	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2014-05-07	Stock Appreciation Right	$24.17	M	3000	Disposed	2016-02-08	Common Stock (3000)	Direct
2014-05-07	Stock Appreciation Right	$25.37	M	2306	Disposed	2017-02-21	Common Stock (2306)	Direct

Footnotes

F1: Stock Appreciation Rights (SARs) are being exercised pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 25, 2014.

F2: 1,446 shares are being surrendered as allowed by the Company's 2005 Stock Incentive Plan to cover the payment of taxes currently due on the exercise of stock appreciation rights.

F3: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 25, 2014.