<PAGE>   1
                                                                   EXHIBIT 10.11

                                    AGREEMENT

         AGREEMENT dated April 30, 1998, between Reliant Building Products, Inc.
("Building Products") and Thomas M. Seymour ("Executive").

         WHEREAS, Building Products desires to employ Executive to assure itself
of the continued services of Executive;

         WHEREAS, Building Products is willing to set forth the minimum
severance benefits which Building Products agrees will be provided to Executive
in the event Executive's employment with Building Products is terminated at any
time;

         WHEREAS, absent this Agreement, Building Products is under no legal
obligation to provide additional compensation to Executive in addition to the
compensation and benefits Executive is proposed to receive; and

         WHEREAS, Executive is willing to serve in the employ of Building
Products and to provide continued dedicated services to Building Products and
its subsidiaries, on a full time basis.

         NOW, THEREFORE, in consideration of the mutual covenants and agreements
herein contained, and other good and valuable consideration, the receipt and
sufficiency all of which are hereby acknowledged, the parties hereto agree as
follows:

         1. Employment. Building Products hereby agrees to employ Executive, and
Executive agrees to provide dedicated services to Building Products and its
subsidiaries, on a full time basis on the terms and conditions set forth herein.

         2. Position and Duties. Executive shall serve as Senior Vice President
of Sales and Marketing of Building Products and shall have such
responsibilities, powers and duties as are normally attendant such position, and
as may from time to time be prescribed by the President or Board of Directors of
Building Products.

         3. Compensation. Executive shall receive a base salary at the annual
rate of at least $210,000.00 (the "Minimum Rate"), subject to increase from time
to time in the sole discretion of Building Products. Any increase in Base Salary
or other compensation shall in no way limit or reduce any other obligation of
Building Products hereunder.

         4. Benefits: Vacation. Executive shall be entitled (a) to participate
in or receive benefits- under all compensation plans, insurance plans, benefit
plans and fringe benefit plans or arrangements presently in effect (or plans and
arrangements providing Executive with substantially similar benefits), and shall
be eligible to participate in any such plans or arrangements which are made
available by Building Products in the future TO ITS EXECUTIVES AND KEY
MANAGEMENT EMPLOYEES, AND (B) TO NOT LESS THAN FOUR (4) WEEKS OF PAID VACATION
each year, together with all paid holidays given to senior EXECUTIVE officers.
Nothing paid to Executive under an such plan or arrangement shall be deemed to
be in lieu of compensation to Executive hereunder.



<PAGE>   2


         5. Termination.

               (a) Termination for Any Reason. Building Products may terminate
Executive's employment at any time subject to providing the severance benefits,
if any, as hereinafter specified according to the terms hereof. The "Date of
Termination" shall mean the date on which Executive's employment hereunder
terminates, and shall be specified in a written notice.

               (b) Termination for Cause. Building Products may terminate
Executive's employment for Cause. For the purposes of this Agreement, Cause
shall mean i) the deliberate and willful failure by Executive to substantially
perform Executive's duties with Building Products, other than any such failure
resulting from Executive's incapacity due to physical or mental illness, or ii)
the willful engaging by Executive in gross misconduct injurious to Building
Products in the sole determination of the Board of Directors of Building
Products acting in good. faith, or iii) the conviction of Executive of fraud,
misappropriation, embezzlement or any felony. For purposes of this subparagraph,
no act, or failure to act, on the Executive's part shall be considered "willful"
unless done, or omitted to be done, by Executive not in good faith and without
reasonable belief by Executive that Executive's action or omission was in the
best interest of Building Products.

               (c) Termination for Disability: Retirement.

                       (i) If, as a result of Executive's incapacity due to
physical or mental illness, Executive shall have been absent from his duties
with Building Products on a full time basis for six (6) consecutive months, and
within thirty (30) days after written notice of termination is given, Executive
shall not have returned to the full time performance of Executive's duties,
Building Products may terminate this Agreement for "Disability".

                       (ii) Termination by Building Products or Executive of
Executive's employment based on "Retirement" shall mean termination at normal
retirement age in accordance with Building Product's retirement policy,
generally applicable to its salaried Executives or in accordance with any
retirement arrangement established with Executive's consent with respect to
Executive.

         6. Compensation Upon Termination.

               (a) Upon termination of Executive's employment by Building
Products for any reason other than for Cause, Disability, Retirement or Death,
in lieu of any severance payments that would otherwise be due Executive upon
termination of his employment, which severance benefits are hereby waived and
relinquished by Executive, Building Products shall:

                       (i) PAY EXECUTIVE, EXECUTIVE'S FULL BASE SALARY THROUGH
THE DATE OF TERMINATION at the rate in effect at the time notice of termination
is given (but in no event less than the Minimum Rate), and a bonus, with respect
to the immediately preceding fiscal year then ended (provided same has not
already been paid) which accrued to Executive;

                       (ii) pay Executive, for all accrued and unused vacation
through the Date of Termination;

                       (iii) pay Executive, Executive's full base salary at the
rate in effect at the time notice of termination is given (but in no event less
than the Minimum Rate), for one (1) year after the Date of Termination plus the
pro rata share of a bonus, if any, with respect to then current fiscal year to
which the Executive would otherwise be entitled but for the termination of
Executive's employment, based upon the factors used in determining the bonus


<PAGE>   3


provided to Executive for Building Products' previous fiscal year. Such bonus
shall be determined in good faith determination of the Board of Directors of
Building Products; and

                       (iv) maintain in full force and effect, for the continued
benefit of Executive for one (1) year after the Date of Termination,
hospitalization, medical insurance, and, life insurance; provided that
Executive's continued participation is possible under the general terms and
provisions of such plans and programs. In the event that Executive's
participation in any such plan or program is barred, Building Products shall
arrange to provide Executive with benefits substantially similar to those which
Executive is entitled to receive under such plans and programs.

               (b) Executive shall not be required to mitigate the amount of any
payment provided for in subparagraph 6 (iii) hereof by seeking other employment
or otherwise, provided, however, that should Executive obtain other employment,
the amounts of any salary and bonus provided to Executive pursuant to such
subsequent employment shall offset amounts otherwise due under subparagraph 6
(iii) hereof. Building Products shall no longer have an obligation to provide
benefits relating to hospitalization, medical insurance, and life insurance to
the extent Executive is covered by any hospitalization, medical insurance, and
life insurance pursuant to such subsequent employment.

               (c) Upon termination of Executive's employment for Cause,
Building Products shall pay Executive Executive's full base salary through the
Date of Termination at the rate in effect at the time notice of termination is
given (but in no event less than the Minimum Rate), and Building Products shall
have no further obligations to Executive under this Agreement.

               (d) During any period that the Executive fails to perform
Executive's duties hereunder as a result of incapacity due to physical or mental
illness, Building Products shall pay Executive Executive's full base salary
through the Date of Termination at the rate in effect at the time notice of
termination is given (but in no event less than the Minimum Rate), and Building
Products shall have no further obligations to Executive under this Agreement.

        7. Unauthorized Disclosure. DURING THE PERIOD OF EXECUTIVE'S EMPLOYMENT
HEREUNDER, EXECUTIVE ACKNOWLEDGES AND AGREES THAT ALL OF THE


<PAGE>   4


documents and information to which he has had access during his employment,
including, but not limited to, this Agreement, all information pertaining to any
specific business transactions in which Building Products was involved, all
information pertaining in any way to customers of Building Products, and in
general, the business and operations of Building Products, are considered
confidential and that during the period of Executive's employment hereunder, and
for the two (2) year period thereafter following termination of Executive's
employment with Building Products, he shall not disclose to any person, other
than an employee of Building Products or a person to whom disclosure is
reasonably necessary or appropriate in connection with the performance by
Executive of his duties as an executive of Building Products or any subsidiary
thereof (individually or collectively as the context may require, the "Building
Products Group"), material confidential information obtained by him while in the
employ of Building Products including, but not limited to confidential
information with respect to any of the Building Products Group's products,
improvements, formulas, customers, distribution of products or methods of
manufacture; provided, however, that confidential information shall not include
any information a) known generally to the public (other than as a result of
unauthorized disclosure by Executive), b) otherwise known or available to
Executive prior to his employment by Building Products, or c) not treated as
confidential by Building Products, except that Executive may disclose (a) the
existence of and the terms of this Agreement to Executive's spouse, attorney,
accountant or tax return preparer if such person has agreed to keep its
existence and provisions confidential, (b) to the extent required by judicial
process, and (c) with the written consent of the Building Products' Board of
Directors or a person authorized thereby.

         8. Non-Compete. Executive agrees that, following termination of his
employment with Building Products for any reason whatsoever and provided
Executive receives compensation pursuant to paragraph 6 (ill) hereunder,
Executive shall not, for a period of one (1) year after the date of such
termination of employment, i) directly or indirectly, carry on or conduct, in
competition with any member of the Building Products Group, any business of the
nature in which the members of the Building Products Group are then engaged, and
of the nature in which Executive was employed by Building Products for any
portion of the period of one (1) year immediately prior to such termination of
employment, in any geographic area or territory in which any member of the
Building Products Group is then engaged in such business, and ii) directly or
have others on his behalf solicit, induce or encourage any employee of the
Building Products Group to leave his or her employment.

         9. Notice. For the purposes of this Agreement, notices and all other
communications provided for in the Agreement shall be in writing and shall be
deemed to have been duly given when delivered or mailed by United States
registered mail, return receipt requested, postage prepaid, addressed as
follows:


<PAGE>   5


      If to Executive:                      If to Building Products:
      Thomas M. Seymour                     Board of Directors
      25921 Edinborough Circle              Reliant Building Products, Inc.
      Perryburg, Ohio 43551-9544            3030 LBJ Freeway, Suite 300
                                            Dallas, Texas 75234

or to such other address as any party hereto may have furnished to the other in
writing.

         10. Miscellaneous.

               (i) No provision of this Agreement may be amended, modified,
waived or discharged unless such amendment, modification, waiver or discharge is
agreed to in writing signed by Executive and such officer as may be specifically
designated by the Board of Directors of Building Products.

               (ii) No waiver by either party hereto at any time of any breach
by the other party hereto of, or compliance with, any condition or provision of
this Agreement to be performed by such other party shall be deemed a waiver of
similar or dissimilar provisions or conditions at the same or at any prior or
subsequent time.

               (iii) The validity, interpretation, construction and performance
of this Agreement shall be governed by the laws of the state of Texas.

               (iv) The invalidity or unenforceability of any provision of this
Agreement shall not affect the validity or enforceability or any other provision
of this Agreement, which shall remain in full force and effect provided,
however, that if any provision of this Agreement is deemed or held to be
illegal, invalid, or unenforceable there shall be added hereto automatically a
provision as similar as possible to such illegal, invalid, or unenforceable
provision and be legal, valid, and enforceable.

               (v) This Agreement shall inure to the benefit of and be
enforceable by Executive's personal or legal representatives, executors,
administrators, successors, heirs, distributees, devisees and legatees. If
Executive should die while any amount would still be payable to Executive
hereunder if Executive had continued to live, all such amounts, unless otherwise
provided herein, shall be paid in accordance with the terms of this Agreement to
Executive's devisee, legatee, or other designee or, if there be no such
designee, to Executive's estate.

               (vi) This Agreement shall be binding upon Building Products and
Building Products' successors and assigns. Building Products will require any
successor (whether direct or indirect, by purchase, merger, consolidation or
otherwise) to all or substantially all of the business and/or assets of Building
Products, to expressly assume and agree to perform this Agreement in the same
manner and to the same extent that Building PRODUCTS WOULD BE REQUIRED to
perform It if no such succession had taken place. Failure of Building Products
to obtain such agreement prior to the effectiveness of ANY SUCH SUCCESSION SHALL

<PAGE>   6


constitute a breach of this Agreement and shall entitle Executive to
compensation from Building Products in accordance with paragraphs 6 (a) and (b)
hereof.

               (vii) This Agreement may be executed in one or more counterparts,
each of which shall be deemed to be an original but all of which together will
constitute one and the same instrument.

         11. Executive acknowledges that he has read this Agreement, that his
execution hereof is knowing and voluntary, that Executive had a reasonable time
to deliberate regarding this Agreement, and that Executive understands that he
had the right to consult with an attorney regarding this Agreement.

         12. No right or interest of Executive hereunder may be sold, assigned,
transferred or pledged, in whole or in part, by operation of law or otherwise by
Executive.

         13. The Parties agree that this Agreement: (a) contains and constitutes
the entire understanding and agreement between them respecting the subject
matter hereof, (b) supersedes and cancels any previous discussions,
negotiations, agreements, commitments and writings respecting that subject
matter, and (c) shall not be deemed or construed to create a trust fund or grant
a security interest of any kind for the benefit of Executive, and to the extent
that Executive acquires any rights to receive the severance payments hereunder,
such rights shall be no greater than the right of any unsecured general creditor
of Building Products.

         IN WITNESS WHEREOF, this Agreement has been executed as of the day and
year first above written.

  RELIANT BUILDING PRODUCTS, INC.                      EXECUTIVE



By: /s/ David G. Fiore                             By: /s/ Thomas M. Seymour
   ---------------------------------                  -------------------------
   David G. Fiore                                     Thomas M. Seymour
   President




                                                                  CONFORMED COPY