THIRD AMENDMENT TO REIMBURSEMENT AND CREDIT AGREEMENT

Exhibit 10.33

EXECUTION COPY

THIRD AMENDMENT TO REIMBURSEMENT AND CREDIT AGREEMENT

dated as of and effective November 21, 2006

By and Between

Trex Company, Inc.

and

JPMorgan Chase Bank, N.A., as Issuing Bank and Administrative Agent

in connection with the Letter of Credit

securing

$25,000,000

Mississippi Business Finance Corporation

Variable Rate Demand Environmental Improvement Revenue Bonds

(Trex Company, Inc. Project), Series 2004

THIRD AMENDMENT TO REIMBURSEMENT AND CREDIT AGREEMENT

TABLE OF CONTENTS

This Table of Contents is not a part of this Third Amendment to Reimbursement and Credit Agreement and is only for convenience of reference.

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THIRD AMENDMENT TO REIMBURSEMENT AND CREDIT AGREEMENT

THIS THIRD AMENDMENT TO REIMBURSEMENT AND CREDIT AGREEMENT (this “Third Amendment”), dated as of and effective November 21, 2006, between TREX COMPANY, INC., a Delaware corporation (the “Borrower” ) and JPMorgan Chase Bank, N.A., as Issuing Bank (in such capacity the “Bank” ) and Administrative Agent (in such capacity the “Administrative Agent” ).

BASIS FOR THIS THIRD AMENDMENT

1. This Third Amendment is authorized by Section 11.03 of the Reimbursement and Credit Agreement dated as of December 1, 2004, among the Borrower, the Bank and the Administrative Agent (the “Original Agreement”). The terms, conditions and provisions of the Original Agreement, as amended by the First Amendment to Reimbursement and Credit Agreement dated July 25, 2005, among the Borrower, the Bank and the Administrative Agent (the “First Amendment”) and the Second Amendment to Reimbursement and Credit Agreement dated as of and effective December 31, 2005 (the “Second Amendment” and together with the Original Agreement and the First Amendment, the “Amended Agreement”) are incorporated into this Third Amendment by reference to the same extent and with the same force and effect as if fully stated in this Third Amendment.

2. The Borrower, the Bank and the Administrative Agent have agreed to a further amendment to (a) Section 6.12 of the Original Agreement in order to provide a new ratio of Funded Net Debt to Consolidated EBITDA on December 31, 2006 and March 31, 2007 and (b) Section 7.01 in order to permit an increase in the amount of Debt outstanding under the BBT Agreement.

3. In consideration of the premises and of the mutual covenants herein contained, and for good and valuable consideration, the Bank, the Administrative Agent and the Borrower do mutually covenant and agree, as follows:

Section 1. Definitions; Rules of Interpretation .

1.1 Definitions . For purposes of this Third Amendment, all capitalized words and phrases not defined in this Third Amendment shall have the meanings given to them in Section 1.01 of the Original Agreement.

1.2 Rules of Interpretation . For all purposes of the Agreement the following shall govern, except as otherwise expressly provided for or unless the context otherwise requires:

(i) The “Agreement” shall mean the Amended Agreement as modified, altered, amended or supplemented by this Third Amendment and as it may from time to time be further modified, altered, amended or supplemented.

(ii) All references in this Third Amendment to designated “Sections” and other subdivisions are to the designated Sections and other subdivisions of the Original Agreement unless otherwise indicated.

(iii) Terms defined in this Third Amendment shall have the meanings prescribed for them where defined herein.

(iv) All accounting terms not otherwise defined in this Third Amendment shall have the meanings assigned to them in accordance with the Original Agreement.

(v) Words of the masculine gender shall be deemed and construed to include correlative words of the feminine and neuter genders.

(vi) Terms in the singular include the plural and vice vers