TREX CO INC — Director's Dealing 2016

May 13, 2016

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TREX CO INC (TREX)
CIK: 0001069878
Period of Report: 2016-05-11

Reporting Person: Cline James E (Director, President and CEO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2016-05-11	Common Stock	M	11946	$13.10	Acquired	105240	Direct
2016-05-11	Common Stock	D	3630	$43.11	Disposed	101610	Direct
2016-05-11	Common Stock	F	3967	$43.11	Disposed	97643	Direct
2016-05-11	Common Stock	S	2037	$43.0522	Disposed	95606	Direct
2016-05-12	Common Stock	S	4349	$43.1316	Disposed	91257	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2016-05-11	Stock Appreciation Right	$13.10	M	11946	Disposed	2022-02-16	Common Stock (11946)	Direct

Footnotes

F1: Stock Appreciation Rights are being exercised pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 18, 2015.

F2: 3,967 shares are being surrendered as allowed by the Company's 2014 Stock Incentive Plan to cover the payment of taxes currently due on the exercise of SARs.

F3: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 18, 2015.

F4: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $42.11 to $43.35, inclusive. The reporting person undertakes to provide Trex Company, Inc. any security holder of Trex Company, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in Footnote (4) to this Form 4.

F5: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $43.00 to $43.37, inclusive. The reporting person undertakes to provide Trex Company, Inc., any security holder of Trex Company, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in Footnote (5) to this Form 4.