TREX CO INC — Director's Dealing 2010

May 11, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TREX CO INC (TREX)
CIK: 0001069878
Period of Report: 2010-05-07

Reporting Person: Gupp William R. (VP,General Counsel & Secretary)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-05-07	Common Stock	F	1992	$21.77	Disposed	42596	Direct
2010-05-10	Common Stock	S	3428	$23.00	Disposed	39168	Direct
2010-05-10	Common Stock	M	5000	$9.14	Acquired	44168	Direct
2010-05-10	Common Stock	D	1976	$23.13	Disposed	42192	Direct
2010-05-10	Common Stock	F	1278	$23.13	Disposed	40914	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2010-05-10	Stock Appreciation Right	$9.14	M	5000	Disposed	2018-05-07	Common Stock (5000)	Direct

Footnotes

F1: 1,992 shares are being surrendered as allowed by the Company's 2005 Stock Incentive Plan to cover the payment of taxes currently due on previously granted restricted shares

F2: 5,000 Stock Appreciation Rights (SARs) are being exercised which were granted pursuant to the Company's 2005 Stock Incentive Plan on May 7, 2008.

F3: 1,278 shares are being surrendered to cover payment of taxes currently due on the exercise of SARs.

F4: The stock appreciation right becomes exerciseable in three equal installments beginning on the first anniversary date of the transaction date.