TREX CO INC — Director's Dealing 2011

Mar 3, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TREX CO INC (TREX)
CIK: 0001069878
Period of Report: 2011-03-01

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-03-01	Common Stock	M	2000	$9.14	Acquired	40613	Direct
2011-03-01	Common Stock	D	594	$30.78	Disposed	40019	Direct
2011-03-01	Common Stock	F	594	$30.78	Disposed	39425	Direct
2011-03-01	Common Stock	S	450	$29.92	Disposed	38975	Direct
2011-03-01	Common Stock	S	100	$30.57	Disposed	38875	Direct
2011-03-01	Common Stock	S	300	$30.575	Disposed	38575	Direct
2011-03-01	Common Stock	S	500	$30.56	Disposed	38075	Direct
2011-03-01	Common Stock	S	200	$30.58	Disposed	37875	Direct
2011-03-01	Common Stock	S	200	$30.55	Disposed	37675	Direct
2011-03-01	Common Stock	S	200	$30.565	Disposed	37475	Direct
2011-03-01	Common Stock	S	100	$30.5575	Disposed	37375	Direct
2011-03-01	Common Stock	S	200	$30.555	Disposed	37175	Direct
2011-03-01	Common Stock	S	203	$30.59	Disposed	36972	Direct
2011-03-01	Common Stock	S	200	$30.51	Disposed	36772	Direct
2011-03-01	Common Stock	S	100	$30.5025	Disposed	36672	Direct
2011-03-01	Common Stock	S	100	$30.50	Disposed	36572	Direct
2011-03-01	Common Stock	S	400	$30.505	Disposed	36172	Direct
2011-03-01	Common Stock	S	200	$30.5025	Disposed	35972	Direct
2011-03-01	Common Stock	S	400	$30.515	Disposed	35572	Direct
2011-03-01	Common Stock	S	200	$30.53	Disposed	35372	Direct
2011-03-01	Common Stock	S	700	$30.52	Disposed	34672	Direct
2011-03-01	Common Stock	S	200	$30.54	Disposed	34472	Direct
2011-03-01	Common Stock	M	550	$20.00	Acquired	35022	Direct
2011-03-02	Common Stock	M	3953	$20.00	Acquired	38975	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-03-01	Stock Appreciation Right	$9.14	M	2000	Disposed	2018-05-07	Common Stock (2000)	Direct
2011-03-01	Stock Options (Right to Buy)	$20.00	M	550	Disposed	2012-02-21	Common Stock (550)	Direct
2011-03-02	Stock Options (Right to Buy)	$20.00	M	3953	Disposed	2012-02-21	Common Stock (3953)	Direct

Footnotes

F1: 594 shares are being surrendered to cover payment of taxes currently due on the exercise of SARs.

F2: 2,000 Stock Appreciation Rights (SARs) are being exercised which were granted pursuant to the Company's 2005 Stock Incentive Plan on May 7, 2008.

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

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