<PAGE>
 
                                 EXHIBIT 10.38

                                FOURTH AMENDMENT
                                       TO
                          LOAN AND SECURITY AGREEMENT
                             AND WAIVER OF DEFAULTS


     THIS FOURTH AMENDMENT TO LOAN AND SECURITY AGREEMENT AND WAIVER OF DEFAULTS
(the "Amendment") is dated as of April 1, 1998, and entered into by and between
BANKAMERICA BUSINESS CREDIT, INC. ("Lender"), a Delaware corporation with
offices at 55 South Lake Avenue, Suite 900, Pasadena, California 91101, and
NATIONAL HOME CENTERS, INC. ("Borrower"), an Arkansas corporation, with offices
at P. 0. Box 789, Highway 265 North, Springdale, Arkansas 72765.

     WHEREAS, Lender and Borrower have entered into a Loan and Security
Agreement dated as of December 19, 1995 (as amended by (i) that certain First
Amendment to Loan and Security Agreement dated as of May 20, 1996, (ii) that
certain Second Amendment to Loan and Security Agreement dated as of April 30,
1997, and (iii) that certain Third Amendment to Loan and Security Agreement
dated as of February 23, 1998, the "Agreement");

     WHEREAS, three Events of Default have occurred under the Agreement;

     WHEREAS, the Borrower desires that the Lender waive the Events of Default
and amend the Agreement in certain respects; and

     WHEREAS, the Lender is willing to waive the Events of Default and amend the
Agreement subject to the terms and conditions contained herein;

     NOW, THEREFORE, in consideration of the mutual conditions and agreements
set forth in the Agreement and this Amendment, and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties, intending to be legally bound, hereby agree as follows:

                                   ARTICLE I
                                        
                                  Definitions
                                        
     Section 1.01. Definitions. Capitalized terms used in this Amendment, to the
extent not otherwise defined herein, shall have the same meanings as in the
Agreement, as amended hereby.

     Section 1.02. Definition of " Availability". The definition of
"Availability, is hereby amended in its entirety to read as follows:

     "Availability" means at any time the lesser of:

          A.   The Maximum Revolving Center Line or

          B.   The sum of
<PAGE>
 
               (1) up to eighty-five percent (85%) of the value of Eligible
                   Accounts, plus

               (2) the lesser of

                   (a) (i) $14,000,000 through May 31, 1998 and (ii)
                   $12,500,000 from June 1, 1998 until the Stated Termination
                   Date; or

                   (b)  the Inventory Advance Rate.

provided, however, that at all times Availability shall be reduced by the sum
of:

     (i)   the unpaid balance of Revolving Loans at that time;

     (ii)  the aggregate undrawn face amount of all outstanding Letters or
Credit and the aggregate outstanding amount of all acceptances which the Lender
has, or has caused to be, issued or obtained for the Borrower's account;

     (iii) reserves for accrued interest on the Revolving Loans;

     (iv)  the Environmental Compliance Reserve;

     (v)   reserves, to be established at Lender's sole discretion, for the
accounts payable to any supplier of consigned and floor-planned Inventory;

     (vi)  the ACH Settlement Risk Reserve; and

     (vii) all other reserves which the Lender in its reasonable discretion
deems necessary or desirable to maintain with respect to the Borrower's account,
including, without limitation, any amounts which the Lender may be obligated to
pay in the future for the account the Borrower."

     Section 1.03. Definition of "Maximum Revolving Credit Line". The definition
of "Maximum Revolving Credit Line" is hereby amended in its entirety to read as
follows:

     "Maximum Revolving Credit Line" means Twenty-Five Million and No/100
     Dollars ($25,000,000.00) through December 31, 1998 and Twenty Million
     Dollars ($20,000,000.00) thereafter.

     Section 1.04. Article I of the Agreement is amended by the addition of the
following definitions:

     "EBITDA" means, with respect to the Borrower and its Subsidiaries, their
     earnings (without taking into account any gain or loss from the sale of
     assets) before taking into account interest, taxes, depreciation and
     amortization.

     "Fayetteville Real Property" means Borrower's Real Property located at 675
     East Joyce, Fayetteville, Arkansas 72703, which Borrower intends to sell
     for at least $6,000,000.
<PAGE>
 
                                   ARTICLE II
                                        
                                   AMENDMENTS

     Section 2.01. Amendment to Section 3.1(a) of the Agreement. Section 3.1(a)
of the Agreement is hereby amended in its entirety to read as follows:

     "3.1.(a) Interest Rates. Except as otherwise provided herein, effective as
     of February 1, 1998, the Obligations shall bear interest on the unpaid
     principal amount thereof from the date made until paid in full in cash at a
     fluctuating per annum rate (the "Applicable Interest Rate") equal to the
     Reference Rate plus one and one-half percent (1.50%) prior to the sale of
     the Fayetteville Real Property and one and one quarter percent (1.25%)
     thereafter. Each change in the Reference Rate shall be reflected in the
     interest rate described above as of the effective date of such change. All
     interest charges shall be computed on the basis of a year of three hundred
     sixty (360) days and actual days elapsed and will be payable in arrears on
     the first day of each month hereafter."

     The remaining sections of Section 3. 1 are unchanged.

     Section 2.02. Amendment to Section 9. 18 of the Agreement. Section 9.18 of
the Agreement is hereby amended in its entirety to read as follows:

     "9.18. Capital Expenditures. Neither the Borrower nor any of its
     Subsidiaries shall make or incur any Capital Expenditure if, after giving
     effect thereto, the aggregate amount of all Capital Expenditures by the
     Borrower and its Subsidiaries (other than Capital Expenditures used
     directly for the acquisition of additional stores to the extent permitted
     by Section 9.22) during any Fiscal Year would exceed Seven Hundred Fifty
     Thousand and No/100 Dollars ($750,000.00)."

     Section 2.02. Amendment to Section 9.19 of the Agreement. Section 9.19 of
the Agreement is hereby amended in its entirety to read as follows:

     "9.19 EBITDA. The Borrower and its Subsidiaries on a consolidated basis
     will not permit EBITDA to be less than the following amounts at the end of
     the Periods specified below:

              PERIODS                               AMOUNTS
              -------                               -------             

One Fiscal Quarter ending 4/30/98                  $   75,000  

Two Fiscal Quarters ending 7/31/98                 $1,500,000      

Three Fiscal Quarters ending 10/31/98              $2,270,000               

Four Fiscal Quarters ending 01/31/99               $2,860,000                 

One Fiscal Quarter ending 04/30/99                 $  300,000                  

Two Fiscal Quarters ending 07/3/99                 $2,600,000                   
<PAGE>
 
              PERIODS                               AMOUNTS
              -------                               -------             

Three Fiscal Quarters ending 10/31/99              $4,400,000     

Four Fiscal Quarters ending 01/31/00               $4,900,000"      

     Section 2.04. Amendment to Section 9.20 of the Agreement.  Section 9.20 of
the Agreement is hereby amended in its entirety to read as follows:

     "9.20 Minimum Adjusted Tangible Net Worth. The Borrower and its
     Subsidiaries on a consolidated basis will not permit Adjusted Tangible Net
     Worth to be less than the following amounts during the Periods specified
     below as determined as of the last day of each month during such Period:

              PERIOD                                      AMOUNTS
        02/27/98 - 03/31/98                             $ 10,700,000
        04/01/98 - 06/30/98                             $ 10,640,000
        07/01/98 - 09/30/98                             $ 10,760,000
        10/01/98 - 12/31/98                             $ 10,970,000
        01/01/99 - 03/31/99                             $  9,960,000
        04/01/99 - 06/30/99                             $  9,200,000
        07/01/99 - 09/30/99                             $  9,800,000
        10/01/99 - 12/31/99                             $11,200,000"

     Section 2.05. Amendment to Section 9.21 of the Agreement. Section 9.21 of
the Agreement is hereby extended in its entirety to read as follows:

     9.2 1. Minimum Availability.  The Borrower will maintain on a daily basis
     unused Availability (after taking into account all outstanding Revolving
     Loans and issued but underdrawn Letters of Credit) of at least (i) $350,000
     prior to the sale of the Fayetteville Real Property and (ii) $500,000
     following the sale of the Fayetteville Real Property.

     Section 2.06. Amendment to Article 12. The first sentence of Article 12 is
hereby revised to read as follows:

          "The initial term of this Agreement shall terminate on December 20,
          1999 (the "Stated Termination Date")."

          All other provisions of Article 12 remain unchanged.
<PAGE>
 
                                  ARTICLE III
                                        
                                    WAIVERS

     Section 3.01. Waiver of Events of Default.

          (a) The Lender hereby waives the following Events of Default: (i)
     Borrower's Minimum Interest Coverage Ratio for the Fiscal Year ending
     January 31, 1998 was less than 1.00 to 1.0, in breach of Section 9.19 of
     the Loan Agreement; (ii) Borrower's Minimum Adjusted Tangible Net Worth for
     the Fiscal Year ending January 31, 1999 was less than $24,484,000, in
     breach of Section 9.20 of the Loan Agreement, and (iii) Borrower's Debt to
     Adjusted Tangible Net Worth Ratio for the Fiscal Quarter ending January 31,
     1998 was greater than 3.0 to 1 in breach of Section 9.21 of the Loan
     Agreement.

          (b) The foregoing waiver is only applicable to and shall only be
     effective to the extent described above. The waiver is limited to the facts
     and circumstances referred to herein and shall not operate as (i) a waiver
     of or consent to non-compliance with any other section or provision of the
     Loan Agreement, (ii) a waiver of any right, power, or remedy of the Lender
     under the Loan Agreement, or (iii) a waiver of any other Event of Default
     or Event which may exist under the Loan Agreement.



                                   ARTICLE IV
                                        
                 RATIFICATIONS, REPRESENTATIONS AND WARRANTIES

     Section 4.01. Ratifications. The terms and provisions set forth in this
Amendment shall modify and supersede all inconsistent terms and provisions set
forth in the Agreement and, except as expressly modified and superseded by this
Amendment, the terms and provisions of the Agreement, including, without
limitation, all financial covenants contained therein, are ratified and
confirmed and shall continue in full force and effect. Lender and Borrower agree
that the Agreement as amended hereby shall continue to be legal, valid, binding
and enforceable in accordance with its terms.

     Section 4.02. Representations and Warranties. Borrower hereby represents
and warrants to Lender that the execution, delivery and performance of this
Amendment and all other loan documents to which Borrower is or is to be a party
hereunder (hereinafter referred to collectively as the "Loan Documents")
executed and/or delivered in connection herewith, have been authorized by all
requisite corporate action on the part of Borrower and will not violate the
Articles of Incorporation or Bylaws of Borrower.



                                   ARTICLE V
                                        
                              CONDITIONS PRECEDENT

     Section 5.01. Condition. The effectiveness of this Amendment is subject to
the satisfaction of the following conditions precedent (unless specifically
waived in writing by the Lender):
<PAGE>
 
          (a)  Lender shall have received all of the following, each dated
     (unless otherwise indicated) as of the date of this Amendment, in form and
     substance satisfactory to Lender in its sole discretion:

               (i)   Company General Certificate. A certificate executed by the
          Secretary or Assistant Secretary of Borrower certifying (A) that
          Borrower's Board of Directors has met and adopted, approved, consented
          to and ratified the resolutions attached thereto which authorize the
          execution, delivery and performance by Borrower of the Amendment and
          the Loan Documents, (B) the names of the officers of Borrower
          authorized to sign this Amendment and each of the Loan Documents to
          which Borrower is to be a party hereunder, (C) the specimen signatures
          of such officers, (D) that neither the Articles of Incorporation nor
          Bylaws of Borrower have been amended since the date of the Agreement,
          and (E) other matters;

               (ii)  No Material Adverse Change. There shall have occurred no
          material adverse change in the business, operations, financial
          condition, profits or prospects of Borrower, or in the Collateral, and
          the Lender shall have received a certificate of Borrower's chief
          executive officer to such effect;

               (iii) Other Documents. Borrower shall have executed and
          delivered such other documents and instruments as Lender may require.

          (b)  All corporate proceedings taken in connection with the
     transactions contemplated by this Amendment and all documents, instruments
     and other legal matters incident thereto shall be satisfactory to Lender
     and its legal counsel, Jenkens & Gilchrist, a Professional Corporation.

          (c)  Borrower shall have paid to Lender the amount of $60,000 as an
     accommodation fee.


                                   ARTICLE VI
                                        
                                 MISCELLANEOUS

     Section 6.01. Survival of Representations and Warranties. All
representations and warranties made in the Agreement or any other document or
documents relating thereto, including, without limitation, any Loan Document
furnished in connection with this Amendment, shall survive the execution and
delivery of this Amendment and the other Loan Documents, and no investigation by
Lender or any closing shall affect the representations and warranties or the
right of Lender to rely thereon.

     Section 6.02. Reference to Agreement. The Agreement, each of the Loan
Documents, and any and all other agreements, documents or instruments now or
hereafter executed and delivered pursuant to the terms hereof or pursuant to the
terms of the Agreement as amended hereby, are hereby amended so that any
reference therein to the Agreement shall mean a reference to the Agreement as
amended hereby.
<PAGE>
 
     Section 6.03. Severability. Any provision of this Amendment held by a court
of competent jurisdiction to be invalid or unenforceable shall not impair or
invalidate the remainder of this Amendment and the effect thereof shall be
confined to the provision so held to be invalid or unenforceable.

     Section 6.04. APPLICABLE LAW. THIS AMENDMENT AND ALL OTHER LOAN DOCUMENTS
EXECUTED PURSUANT HERETO SHALL BE DEEMED TO HAVE BEEN MADE AND TO BE PERFORMABLE
IN THE STATE OF CALIFORNIA AND SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE
WITH THE LAWS OF THE STATE OF CALIFORNIA.

     Section 6.05. Successors and Assigns. This Amendment is binding upon and
shall inure to the benefit of Lender and Borrower and their respective
successors and assigns; provided, however, that Borrower may not assign or
transfer any of its rights or obligations hereunder without the prior written
consent of Lender. Lender may assign any or all of its rights or obligations
hereunder without the prior consent of Borrower.

     Section 6.06. Counterparts. This Amendment may be executed in one or more
counterparts, each of which when so executed shall be deemed to be an original,
but all of which when taken together shall constitute one and the same
instrument.

     Section 6.07. Effect of Waiver. No consent or waiver, express or implied,
by Lender to or of any breach of or deviation from any covenant or condition of
the Agreement or duty shall be deemed a consent or waiver to or of any other
breach of or deviation from the same or any other covenant, condition or duty.
No failure on the part of Lender to exercise and no delay in exercising, and no
course of dealing with respect to, any right, power, or privilege under this
Amendment, the Agreement or any other Loan Document shall operate as a waiver
thereof, nor shall any single or partial exercise of any right, power, or
privilege under this Amendment, the Agreement or any other Loan Document
preclude any other or further exercise thereof or the exercise of any other
right, power, or privilege. The rights and remedies provided for in the
Agreement and the other Loan Documents are cumulative and not exclusive of any
rights and remedies provided by law.

     Section 6.08. Heading. The headings, captions and arrangements used in this
Amendment are for convenience only and shall not affect the interpretation of
this Amendment.

     Section 6.09. Releases. As a material inducement to Lender to enter into
this Amendment, Borrower hereby represents and warrants that there are no claims
or offsets against, or defenses or counterclaims to, the terms and provisions of
and the other obligations created or evidenced by the Agreement or the other
Loan Documents. Borrower hereby releases, acquits, and forever discharges
Lender, and its successors, assigns, and predecessors in interest, their
parents, subsidiaries and affiliated organizations, and the officers, employees,
attorneys, and agents of each of the foregoing (all of whom are herein jointly
and severally referred to as the "Released Parties") from any and all liability,
damages, losses, obligations, costs, expenses, suits, claims, demands, causes of
action for damages or any other relief, whether or not now known or suspected,
of any kind, nature, or character, at law or in equity, which Borrower now has
or may have ever had against any of the Released Parties, including, but not
limited to, those relating to (a) usury or penalties or damages therefor, (b)
allegations that a partnership existed between Borrower and the Released
Parties, (c) allegations of unconscionable acts, deceptive trade practices, lack
of good faith or fair dealing, lack of commercial reasonableness or special
relationships, such as fiduciary, trust or confidential relationships, (d)
allegations of dominion, 
<PAGE>
 
control, alter ego, instrumentality, fraud, misrepresentation, duress, coercion,
undue influence, interference or negligence, (e) allegations of tortuous
interference with present or prospective business relationships or of antitrust,
or (f) slander, libel or damage to reputation (hereinafter being collectively
referred to as the "Claims"), all of which Claims are hereby waived.

     Section 6.10. Expenses of Lender. Borrower agrees to pay on demand (i) all
costs and expenses reasonably incurred by Lender in connection with the
preparation, negotiation and execution of this Amendment and the other Loan
Documents executed pursuant hereto and any and all subsequent amendments,
modifications, and supplements hereto or thereto, including, without limitation,
the costs and fees of Lender's legal counsel and the allocated cost of staff
counsel and (ii) all costs and expenses reasonably incurred by Lender in
connection with the enforcement or preservation of any rights under the
Agreement, this Amendment and/or other Loan Documents, including, without
limitation, the costs and fees of Lender's legal counsel and the allocated cost
of staff counsel.

     Section 6.11. NO ORAL AGREEMENTS. THIS AMENDMENT, TOGETHER WITH THE OTHER
LOAN DOCUMENTS AS WRITTEN, REPRESENT THE FINAL AGREEMENTS BETWEEN LENDER AND
BORROWER AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS OR
SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL
AGREEMENTS BETWEEN LENDER AND BORROWER.

     IN WITNESS WHEREOF, the parties have executed this Amendment under seal on
the date first above written.

                                       "BORROWER"



ATTEST:                                NATIONAL HOME CENTERS, INC.



                                       By:
----------------------------------        --------------------------------------
Secretary                              Name:
(Corporate Seal)                            ------------------------------------
                                       Title:
                                             -----------------------------------


     AGREED AND ACCEPTED as of the date first written above.

                                       "LENDER"

                                       BANKAMERICA BUSINESS CREDIT, INC.


                                       By:
                                          --------------------------------------
                                       Name:
                                            ------------------------------------
                                       Title:
                                             -----------------------------------