Exhibit 10.21

DIRECTOR/OFFICER INDEMNIFICATION AGREEMENT

THIS AGREEMENT made as of the              day of December, 2008, between
                                                      (“Director/Officer”) and
TREX COMPANY, INC., a Delaware corporation (the “Corporation”), provides:

1. General. Director/Officer is currently serving as a member of the Board of
Directors of the Corporation (the “Board”) and as an officer of the Corporation.
As an inducement for Director/Officer to continue to serve as a member of the
Board and as an officer of the Corporation, the Corporation has agreed to enter
into this Agreement.

2. Indemnification. The Corporation agrees, to the fullest extent now or
hereafter permitted by applicable law, including but not limited to the General
Corporation Law of the State of Delaware, to indemnify Director/Officer against
any liability imposed upon or asserted against him (including amounts paid in
settlement) in any proceeding (including a proceeding by or in the right of the
Corporation) arising out of acts or omissions in his capacity as a member of the
Board or officer of the Corporation or otherwise by reason of the fact that he
is or was a member of the Board or officer of the Corporation.

3. Advancement of Expenses. The Corporation will advance, pay for and/or
reimburse the reasonable expenses incurred by Director/Officer if he is a party
to any proceeding described in Section 2 above in advance of the final
disposition thereof if Director/Officer furnishes the Corporation a written
undertaking, executed personally or on his behalf, to repay the advance if it is
ultimately determined that he is not entitled to indemnification. The
undertaking required by the preceding sentence shall be an unlimited general
obligation of Director/Officer but need not be secured and need not be
accompanied by evidence of financial ability to make repayment.

4. Limitation of Damages. The foregoing provisions are intended to provide
indemnification with respect to those monetary damages for which the law of
Delaware permits the limitation or elimination of liability. In addition, to the
full extent that a Delaware corporation now or hereafter is entitled to permit
the limitation or elimination of liability, Director/Officer shall not be liable
to the Corporation or its stockholders for monetary damages arising out of a
single transaction, occurrence or course of conduct.

5. Directors and Officers Liability Insurance. The Corporation will maintain
directors’ and officers’ liability insurance covering Director, in limits and
under other terms that are reasonable and customary for a Company similar in
size and nature to the Corporation, at all times while Director/Officer is
serving on the Board or as an officer of the Corporation and for a period of at
least five (5) years thereafter.

6. Severability. In the event a Court of competent jurisdiction should determine
any provision of this Agreement invalid or unenforceable, the balance of this
Agreement shall remain in full force and effect. In the event such Court should
determine a provision herein to be unreasonable, then such provision shall be
construed in a manner that, as to such Court, may be reasonable.

7. Miscellaneous. The provisions of this Agreement shall be applicable to all
actions, claims suits or proceedings commenced after the date hereof, whether
arising from any action taken or failure to act before or after such date.
Except to the extent inconsistent with this Agreement, terms used herein shall
have the same meanings assigned them in the Indemnification Article of the
Delaware Corporation Law, as now in effect or hereafter amended.

IN WITNESS WHEREOF, the parties hereby have caused this Indemnification
Agreement to be duly executed as of the day and year first above written.

 

  [Name of Director/Officer] Trex Company, Inc. By   Title