EXHIBIT 5.2

                                  June 22, 2004

Ply Gem Industries, Inc.
303 West Major Street
Kearney, Missouri  64060

      Re:   Ply Gem Industries, Inc. Exchange Offer for $225,000,000 9% Senior
            Subordinated Notes due 2012

Ladies and Gentlemen:

      In connection with the Registration Statement on Form S-4, as amended (the
"Registration Statement"), of Ply Gem Industries, Inc., a Delaware corporation
(the "Company"), and Ply Gem Holdings, Inc., a Delaware corporation
("Holdings"), Great Lakes Window, Inc., an Ohio corporation ("Great Lakes"),
Kroy Building Products, Inc., a Delaware corporation ("Kroy"), Napco, Inc., a
Delaware corporation ("Napco"), Napco Window Systems, Inc., a Delaware
corporation ("NWS"), Thermal-Gard, Inc., a Pennsylvania corporation ("Thermal
Gard"), and Variform, Inc., a Missouri corporation ("Variform") (collectively,
the "Guarantors"), filed with the Securities and Exchange Commission pursuant to
the Securities Act of 1933, as amended (the "Act"), and the rules and
regulations thereunder (the "Rules"), you have asked us, as special counsel in
the State of Missouri to Variform, to furnish the opinions set forth below. The
Registration Statement relates to the registration under the Act of the
Company's $225,000,000 aggregate principal amount of 9% Senior Subordinated
Notes due 2012 (the "Exchange Notes") and the guarantees of the Exchange Notes
by the Guarantors (the "Guarantees")

      The Exchange Notes are to be offered in exchange for the Company's
outstanding $225,000,000 aggregate principal amount of 9% Senior Subordinated
Notes due 2012 (the "Initial Notes") issued and sold by the Company on February
12, 2004 in an offering exempt from registration under the Act. The Exchange
Notes will be issued by the Company in accordance with the terms of the
Indenture (the "Indenture"), dated as of February 12, 2004, among the Company,
the Guarantors and U.S. Bank National Association, as trustee.

      As special counsel to Variform, we have examined originals or copies
(certified or otherwise identified to our satisfaction) of the Indenture, the
form of Exchange Notes and such

Ply Gem Industries, Inc.
June __, 2004
Page 2

corporate records and other documents as we have considered relevant and
necessary for the purposes of this opinion.

      As to matters of fact, we have relied upon representations of officers of
Variform, including but not limited to those set forth in the Certificate of the
Secretary of even date herewith, and upon certain certificates of public
officials. As to matters of law, we express no opinion as to any matter relating
to the laws of any jurisdiction other than the laws of the State of Missouri.

      We have assumed due authorization, execution and delivery of the Indenture
and the other agreements and documents referred to in this opinion by all
parties thereto other than Variform and the enforceability of the Indenture and
such other agreements and documents against such parties. We have also assumed,
without independent investigation, (i) that the Exchange Notes and Guarantees
will be issued as described in the Registration Statement and (ii) that the
Exchange Notes and Guarantees will be in substantially the form attached to the
Indenture and that any information omitted from such form will be properly
added. We have also assumed the correctness of all statements of fact contained
in all agreements, certificates and other documents examined by us; the
correctness of all statements of fact made in response to our inquiries by
officers and other representatives of Variform and by public officials; the
legal capacity of all natural persons; the genuineness of all signatures on all
agreements and other documents examined by us; the authenticity of all documents
submitted to us as originals and the conformity to authentic original documents
of all documents submitted to us as copies. We have also assumed that Variform
has or will receive any consideration required under Missouri law for its
issuance of the Guarantees.

      Based upon, and subject to, the foregoing, we are of the opinion that:

      (i) Variform is validly existing as a corporation and in good standing
under the laws of the State of Missouri.

      (ii) Variform has duly authorized the Guarantees and duly authorized the
performance of its obligations thereunder.

      (iii) Variform has the requisite corporate power and authority to execute,
deliver and perform its obligations under the Guarantees.

Ply Gem Industries, Inc.
June __, 2004
Page 3

      (iv) The issuance, execution and delivery of the Guarantees by Variform
and the performance of its obligations thereunder will not result in a violation
of the certificate of incorporation, as amended, or by-laws, as amended, of
Variform, as certified by Variform, as in effect on the date of the opinion
(collectively, the "Charter Documents") or any Missouri statute, rule or
regulation binding on Variform.

      We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the use of our name under the heading "Legal
Matters" contained in the Prospectus included in the Registration Statement. In
giving this consent, we do not thereby admit that we come within the category of
persons whose consent is required by the Act or the Rules.

      The opinions set forth in this letter are effective as of the date hereof.
We express no opinions other than as herein expressly set forth, and no
expansion of our opinions may be made by implication or otherwise. We do not
undertake to update this letter to reflect any matter which comes to our
attention after the delivery of this letter and disclaim any responsibility to
advise you of future changes in law or fact which may affect the above opinions.

      This opinion letter may not be relied upon by any person other than the
addressee and its counsel Paul, Weiss, Rifkind, Wharton & Garrison LLP.

                                      Very truly yours,


                                      /s/ LATHROP & GAGE L.C.
                                      ---------------------------
                                          LATHROP & GAGE L.C.