TREX CO INC — Director's Dealing 2011

Aug 2, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TREX CO INC (TREX)
CIK: 0001069878
Period of Report: 2011-08-01

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-08-01	Common Stock	M	1875	$9.14	Acquired	36180	Direct
2011-08-01	Common Stock	D	858	$19.99	Disposed	35322	Direct
2011-08-01	Common Stock	F	480	$19.99	Disposed	34842	Direct
2011-08-01	Common Stock	S	389	$20.25	Disposed	34453	Direct
2011-08-01	Common Stock	S	100	$20.04	Disposed	34353	Direct
2011-08-01	Common Stock	S	198	$19.98	Disposed	34155	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-08-01	Stock Appreciation Right	$9.14	M	1875	Disposed	2018-05-07	Common Stock (1875)	Direct

Footnotes

F1: 1,875 Stock Appreciation Rights (SARs) are being exercised pursuant to Rule 10b5-1 trading plan adopted by the reporting person on November 3, 2010.

F2: 480 shares are being surrendered as allowed by the Company's 2005 Stock Incentive Plan to cover payment of taxes currently due on the exercise of SARs.

F3: The sales reported in this Form 4 were effected pursuant to Rule 10b5-1 trading plan adopted by the reporting person on November 3, 2010.

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