<PAGE>

                                                           EXHIBIT 10 (i)(i)



                                AMENDED AND RESTATED CREDIT
                    AGREEMENT (364-Day) dated as of October 21, 1999
                    (this "Amendment and Restatement"), among
                    ARMSTRONG WORLD INDUSTRIES, INC. (the
                    "Borrower"), each lender listed on the signature pages
                    hereof (each individually a "Lender" and collectively the
                    "Lenders") and THE CHASE MANHATTAN BANK, a
                    New York banking corporation, as administrative agent for
                    the Lenders (in its capacity as administrative agent, the
                    "Administrative Agent").


               WHEREAS, on October 29, 1998, the Borrower, The Chase Manhattan
Bank, as Administrative Agent, and certain of the Lenders entered into a 364-Day
Credit Agreement (the "Credit Agreement") pursuant to which the Lenders made
available to the Borrower Loans in an aggregate principal amount of
$450,000,000;

               WHEREAS, the parties hereto desire to amend and restate the
Credit Agreement as set forth herein; and

               WHEREAS, the Borrower and the Lenders have agreed to amend and
restate, on the terms and subject to the conditions set forth herein, the Credit
Agreement, to provide for the foregoing.

               NOW THEREFORE, for and in consideration of the premises and the
mutual covenants herein set forth and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the Borrower, the
Administrative Agent and the Lenders hereby agree as follows:

               SECTION 1. All capitalized terms which are defined in the Credit
Agreement and not otherwise defined herein or in the recitals hereof shall have
the same meanings herein as in the Credit Agreement.

               SECTION 2. All references to Section numbers in this Amended and
Restated Credit Agreement shall, except as the context requires, be references
to the corresponding Sections of the Credit Agreement.

               SECTION 3. The Credit Agreement is hereby amended as follows:

          (a)  the heading is deleted and the following is substituted in lieu
thereof:

                    "AMENDED AND RESTATED 364-DAY CREDIT
                    AGREEMENT dated as of October 21, 1999, among
                    ARMSTRONG WORLD INDUSTRIES, INC. (the
                    "Borrower"), the lenders listed in Schedule 2.01 (the
                    "Lenders") and THE CHASE MANHATTAN BANK,
                    as administrative agent for the Lenders (the
                    "Administrative Agent").

          (b)  Section 1.01 of the Credit Agreement is amended as follows:
<PAGE>

                    (i)    The definition of "Borrower's 1997 Form 10-K" is
          hereby replaced in its entirety by the following:

          "Borrower's 1998 Form 10-K" means the Borrower's annual report on Form
          10-K for 1998, as filed with the Securities and Exchange Commission
          pursuant to the Securities Exchange Act of 1934."

                    (ii)   The definition of "Borrower's Latest Form 10-Q" is
          hereby replaced in its entirety by the following:

               "Borrower's Latest Form 10-Q" means the Borrower's quarterly
          report on Form 10-Q for the quarter ended June 30, 1999, as filed with
          the Securities and Exchange Commission pursuant to the Securities
          Exchange Act of 1934."

                    (iii)  The definition of "Co-Documentation Agents" is hereby
          deleted in its entirety.

                    (iv)   The definition of "Designated Currency" is hereby
          replaced in its entirety by the following:

               "Designated Currency' means Pounds Sterling, Canadian Dollars,
          Australian Dollars, Japanese Yen and the Euro and any other Alternate
          Currency that shall be designated by the Borrower in a notice
          delivered to the Administrative Agent and approved by the
          Administrative Agent and all the Banks as a Designated Currency."

                    (v)    The definition of "Documentation Agent" is hereby
          deleted in its entirety.

                    (vi)   The definition of "Existing Credit Agreement" is
          hereby replaced in its entirety by the following:

               "Existing Credit Agreement' means the Credit Agreement dated as
          of October 29, 1998, among the Borrower, the Banks party thereto and
          The Chase Manhattan Bank, as Administrative Agent."

                    (vii)  The definition of "Syndication Agent" is hereby
          deleted in its entirety:

                    (viii) The definition of "Termination Date" is hereby
          replaced in its entirety by the following:

               "Termination Date' means October 19, 2000, or, if such day is not
          a Eurocurrency Business Day, the next preceding Eurocurrency Business
          Day, as such date may be extended pursuant to Section 2.07."

          (c)  Section 2.06 of the Credit Agreement is hereby amended by
     deleting paragraph (b) thereof.
<PAGE>

          (d)  Section 4.04(a) of the Credit Agreement is hereby amended by (i)
     deleting the date December 31, 1997 therein and inserting the date December
     31, 1998 in lieu thereof and (ii) deleting "Borrower's 1997 Form 10-K" and
     inserting "Borrower's 1998 Form 10-K" in lieu thereof.

          (e)  Section 4.04(b) of the Credit Agreement is hereby amended by
     deleting the date June 30, 1998 therein and inserting the date June 30,
     1999 in lieu thereof.

          (f)  Section 4.04(c) of the Credit Agreement is hereby amended by
     deleting the date June 30, 1998, therein and inserting the date June 30,
     1999 in lieu thereof.

          (g)  Section 4.05 of the Credit Agreement is hereby amended by
     deleting "Borrower's 1997 Form 10-K" and inserting "Borrower's 1998 Form
     10-K" in lieu thereof.

          (h)  The Credit Agreement is hereby amended by inserting a new Section
     4.11 as follows:

                    "Section 4.11. Year 2000. Any reprogramming required to
          permit the proper functioning, in and following the year 2000, of (a)
          the mission critical computer systems of the Borrower and its
          Subsidiaries and (b) mission critical equipment containing embedded
          microchips (including systems and equipment supplied by others or with
          which the Borrower's systems interface) and the testing of all such
          systems and equipment, as so reprogrammed, has been completed. The
          cost to the Borrower and its Subsidiaries of such reprogramming and
          testing and of the reasonably foreseeable consequences of Year 2000 to
          the Borrower and its Subsidiaries (including reprogramming errors and
          the failure of others' systems or Equipment) will not result in a
          Default or a material adverse effect."

          (i)  The definition of "Commencement of the Third Stage of EMU" in
     Section 9.12 of the Credit Agreement is hereby deleted in its entirety.

          (j)  Section 9.12(b) of the Credit Agreement is hereby deleted in its
     entirety.

          (k)  Section 9.12(c) of the Credit Agreement is hereby replaced in its
     entirety by the following:

                    "(b) Redenomination of Certain Foreign Currencies.  Each
               obligation of any party to this Credit Agreement to make a
               payment denominated in the national  currency unit of any member
               state of the European Union that adopts the Euro as its lawful
               currency after the date hereof shall be redenominated into the
               Euro at the time of such adoption (in accordance with the EMU
               Legislation).

          (l)  Section 9.12(d) of the Credit Agreement is deleted in its
     entirety.

          (m)  The Pricing Schedule to the Credit Agreement is hereby amended by
     (i) deleting the 6.50 in Category 2 of the Facility Fee Rate and inserting
     7.00 in lieu thereof and (ii) deleting the 33.50 in Category 2 of the
     Eurocurrency Margin and inserting 33.00 in lieu thereof.

          (n)  The Commitment Schedule to the Credit Agreement is hereby
     replaced in its entirety by the Commitment Schedule attached as Exhibit A
     hereto.
<PAGE>

          (o)  "Effective Date" shall mean the date on which this Amendment and
     Restatement shall become effective in accordance with Section 6 below.

                    SECTION 4. Restatement. The Credit Agreement is hereby
     restated in the form in which it currently exists but with the changes
     provided for in Section 3 above.

                    SECTION 5. Representations and Warranties. The Borrower
     represents and warrants as of the Effective Date to the Administrative
     Agent on behalf of the Lenders that:

          (a)  Before and after giving effect to this Amendment and Restatement,
     the representations and warranties set forth in the Credit Agreement, as
     amended hereby, are true and correct in all material respects with the same
     effect as if made on the Effective Date hereof.

          (b)  Immediately before and after giving effect to this Amendment and
     Restatement, no Event of Default or Default has occurred and is continuing.

                    SECTION 6. Conditions to Effectiveness. This Amendment and
     Restatement shall become effective as of the date hereof when the following
     conditions shall have been satisfied (or waived in accordance with Section
     9.05 of the Credit Agreement):

          (a)  receipt by the Administrative Agent of counterparts hereof signed
     by each of the parties hereto (or, in the case of any party as to which an
     executed counterpart shall not have been received, receipt by the
     Administrative Agent in form satisfactory to it of telegraphic, telex or
     other written confirmation from such party of execution of a counterpart
     hereof by such party);

          (b)  receipt by the Administrative Agent of an opinion of Walter T.
     Gangl, Esq., Deputy General Counsel and Corporate Assistant Secretary of
     the Borrower, substantially in the form of Exhibit A to the Credit
     Agreement and covering such additional matters relating to the transactions
     contemplated hereby as the Administrative Agent may reasonably request;

          (c)  receipt by the Administrative Agent of all documents the
     Administrative Agent may reasonably request relating to the existence of
     the Borrower, the corporate authority for and the validity of this
     Amendment and Restatement, and any other matters relevant hereto, all in
     form and substance satisfactory to the Administrative Agent;

          (d)  receipt by the Administrative Agent of all fees and expense; and

          (e)  termination of the Borrower's existing credit facility dated as
     of February 7, 1995 among the Borrower, the lenders party thereto and
     Morgan Guaranty Trust Company, as administrative agent.

                    SECTION 7. Amendment and Restatement. Except as specifically
     amended herein, the provisions of the Credit Agreement shall remain
     identical in all other respects. As used therein, the terms "Credit
     Agreement", "herein", "hereunder", respects. As used therein, the terms
     "Credit Agreement", "herein", "hereunder", "hereinafter", "hereto",
     "hereof" and words of similar import shall, unless the context otherwise
     requires, refer to the Credit Agreement as amended and restated hereby.
<PAGE>

               SECTION 8. Counterparts. This Amendment and Restatement may be
     executed in any number of counterparts and by different parties hereto in
     separate counterparts, each of which when so executed and delivered shall
     be deemed an original, but all such counterparts together shall constitute
     but one and the same instrument. Delivery of any executed counterpart of a
     signature page of this Amendment and Restatement by facsimile transmission
     shall be as effective as delivery of a manually executed counterpart
     hereof.

               SECTION 9. Applicable Law. THIS AMENDMENT AND RESTATMENT SHALL BE
     GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW
     YORK.

               SECTION 10. Headings. The headings of this Amendment and
     Restatement are for purposes of reference only and shall not limit or
     otherwise affect the meaning hereof.

               IN WITNESS WHEREOF, the parties hereto have caused this Amendment
     and Restatement to be duly executed by their duly authorized officers, all
     as of the date and year first above written.


                                   ARMSTRONG WORLD INDUSTRIES, INC.,

                                     By
                                        /s/ Jeffrey R. Wittenberg
                                        ---------------------------------
                                        Name:  Jeffrey R. Wittenberg
                                        Title: Assistant Treasurer

                                   THE CHASE MANHATTAN BANK, individually
                                   and Administrative Agent,

                                     By

                                        /s/ Robert T. Sacks
                                        ---------------------------------
                                        Name:  Robert T. Sacks
                                        Title: Managing Director


                                   BANK OF AMERICA, NA, formerly known as
                                   BANK OF AMERICA NATIONAL TRUST &
                                   SAVINGS ASSOCIATION,


                                     By

                                        /s/ John W. Pocalyko
                                        ---------------------------------
                                        Name:  John W. Pocalyko
                                        Title: Managing Director
<PAGE>

                                    WACHOVIA BANK, N.A.,

                                      By /s/ James Barwis
                                         ------------------------------
                                         Name:  James Barwis
                                         Title: Vice President



                                    DEUTSCHE BANK AG NEW YORK BRANCH
                                    AND/OR CAYMAN ISLANDS BRANCH,

                                      By /s/ Hans-Josef Thiele
                                         ------------------------------
                                         Name:  Hans-Josef Thiele
                                         Title: Director

                                      By /s/ Joel Makowsky
                                         ------------------------------
                                         Name:  Joel Makowsky
                                         Title: Vice President



                                    BARCLAYS BANK PLC,

                                      By /s/ Terance Bullock
                                         ------------------------------
                                         Name:  Terance Bullock
                                         Title: Vice PresidentBW
                                                CAPITAL MARKETS,
                                                INC.


                                      By /s/ Thomas A. Lowe
                                         ------------------------------
                                         Name:  Thomas A. Lowe
                                         Title: Vice President



                                      By /s/ Kenneth J. Ward
                                         ------------------------------
                                         Name:  Kenneth J. Ward
                                         Title: Chief Financial Officer
<PAGE>

                                    BANQUE NATIONALE DE PARIS,

                                       By /s/ Richard L. Sted
                                          -------------------------------
                                          Name:  Richard L. Sted
                                          Title: Senior Vice President

                                       By /s/ Thomas George
                                          -------------------------------
                                          Name:  Thomas George
                                          Title: Vice President
                                                 Corporate Banking
                                                 Division


                                    UNICREDITO ITALIANO S.P.A.,

                                       By /s/ Christopher Eldin
                                          -------------------------------
                                          Name:  Christopher Eldin
                                          Title: Vice President

                                       By /s/ Saiyed A. Abbos
                                          -------------------------------
                                          Name:  Saiyed A. Abbos
                                          Title: Vice President


                                    CITIBANK N.A.,

                                       By /s/ Stuart G. Miller
                                          -------------------------------
                                          Name:  Stuart G. Miller
                                          Title: Managing Director

                                    FIRST UNION NATIONAL BANK,

                                       By /s/ Joseph M. Del Tito
                                          -------------------------------
                                          Name:  Joseph M. Del Tito
                                          Title: Executive Vice President

                                    BANK ONE, NA (MAIN OFFICE CHICAGO),

                                       By /s/ Stephen E. McDonald
                                          -------------------------------
                                          Name:  Stephen E. McDonald
                                          Title: Senior Vice President
<PAGE>

                                    MORGAN GUARANTY TRUST COMPANY OF
                                    NEW YORK

                                       By /s/ Dennis Wilczek
                                          ------------------------------------
                                          Name:  Dennis Wilczek
                                          Title: Associate


                                    PNC BANK, NATIONAL ASSOCIATION,

                                       By /s/ Brennan T. Danile
                                          ------------------------------------
                                          Name:  Brennan T. Danile
                                          Title: Assistant Vice President

                                    SOCIETE GENERAL FINANCE (IRELAND) LIMITED,

                                       By /s/ Richard Wanless
                                          ------------------------------------
                                          Name:  Richard Wanless
                                          Title: Managing Director


                                       By /s/ Aidan Storey
                                          ------------------------------------
                                          Name:  Aidan Storey
                                          Title: Account Manager

                                    SUNTRUST BANK ATLANTA

                                       By /s/ W. David Wisdom
                                          ------------------------------------
                                          Name:  W. David Wisdom
                                          Title: Vice President


                                    WESTDEUTSCHE LANDESBANK

                                       By /s/ Alan S. Bookspan
                                          ------------------------------------
                                          Name:  Alan S. Bookspan
                                          Title: Director


                                       By /s/ Walter T. Duffy, III
                                          ------------------------------------
                                          Name:  Walter T. Duffy, III
                                          Title: Vice President
<PAGE>

                                    HSBC BANK USA,

                                       By /s/ Anna Yuen
                                          ------------------------------------
                                          Name:  Anna Yuen
                                          Title: Assistant Vice President


                                    THE BANK OF NEW YORK,

                                       By /s/ Walter C. Parelli
                                          -----------------------------------
                                          Name:  Walter C. Parelli
                                          Title: Vice President

                                    SKANDINAVISKA ENSKILDA BANKEN, NEW YORK
                                    BRANCH,

                                       By /s/ Magnus C. Lejstrom
                                          ------------------------------------
                                          Name:  Magnus C. Lejstrom
                                          Title: Vice President

                                       By /s/ Phillip Montemurro
                                          ------------------------------------
                                          Name:  Phillip Montemurro
                                          Title: Vice President


                                    FORTIS (USA) FINANCE LLC,

                                       By /s/ David Snyder
                                          ------------------------------------
                                          Name:  David Snyder
                                          Title: Senior Vice President

                                       By /s/ Eddie Matthews
                                          ------------------------------------
                                          Name:  Eddie Matthews
                                          Title: Senior Vice President
<PAGE>

                              COMMITMENT SCHEDULE

     BANK                                              COMMITMENT
     ----                                              ----------

The Chase Manhattan Bank                               $ 50,000,000

Bank of America N.A.                                   $ 35,000,000

Deutsche Bank AG New York Branch
and/or Cayman Islands Branch                           $ 35,000,000

Morgan Guaranty Trust Company
Of New York                                            $ 35,000,000

Wachovia Bank, N.A.                                    $ 35,000,000

Bank One, NA (Main Office Chicago)                     $ 20,000,000

Barclays Banks PLC                                     $ 20,000,000

Citibank N.A.                                          $ 20,000,000

First Union National Bank                              $ 20,000,000

Marine Midland Bank                                    $ 20,000,000

Societe Generale Finance (Ireland)
Limited                                                $ 20,000,000

Westdeutsche Landesbank                                $ 20,000,000

The Bank of New York                                   $ 15,000,000

Banque Nationale De Paris                              $ 15,000,000

BW Capital Markets, Inc.                               $ 15,000,000

Fortis (USA) Finance LLC                               $ 15,000,000

PNC Bank, National Association                         $ 15,000,000

Skandinaviska Enskilda Banken                          $ 15,000,000

Suntrust Bank, Atlanta                                 $ 15,000,000

Unicredito Italiano S.p.A.                             $ 15,000,000
                                                       ------------
                                                       $450,000,000
<PAGE>

                                PRICING SCHEDULE

          "FACILITY FEE RATE" and "EUROCURRENCY MARGIN" mean, for any date, the
applicable rate set forth below in the row opposite such term based upon the
ratings by S&P and Moody's, respectively, applicable on such date to the Index
Debt:


<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                         Category 1        Category 2        Category 3        Category 4        Category 5        Category 6
                         A/A2 or           A-/A3             BBB+Baal          BBB/Baa2          BBB/Baa2          BBB/Baa3
                         Higher                                                And A2/P2         And not           Or Lower
                                                                                                 A2/Ps
-----------------------------------------------------------------------------------------------------------------------------
<S>                      <C>               <C>               <C>               <C>               <C>               <C>
Eurocurrency               30.00             33.00             37.00             45.00             45.00             62.50
Margin (bp)
-----------------------------------------------------------------------------------------------------------------------------
Facility Fee                5.00              7.00              8.00             10.00             10.00             12.50
Rate (bp)
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

          For purposes of the foregoing, (i) if S&P or Moody's shall not have in
effect a rating for the Index Debt, then such rating agency shall be deemed to
have established a rating in Category 5; (ii) if the ratings established or
deemed to have been established by S&P and Moody's for the Index Debt shall fall
within different categories, the applicable rate shall be based on (A) if the
ratings are in adjacent categories, the higher of the two ratings and (B) if the
ratings are in non-adjacent categories, the rating immediately below the higher
of the two ratings; and (iii) if the ratings established or deemed to have been
established by S&P and Moody's for the Index Debt shall be changed (other than
as a result of a change in the rating system of such rating agency), such change
shall be effective as of the date on which it is first announced by the
applicable rate shall apply during the period commencing on the effective date
of such change and ending on the date immediately preceding the effective date
of the next such change.

          "MOODY'S" means Moody's Investors Service, Inc.

          "S&P" means Standard & Poor's Ratings Services, a division of The
McGraw-Hill Companies, Inc.

          "INDEX DEBT" means the senior unsecured long-term debt securities of
the Borrower without third-party enhancement, and any rating assigned to any
other debt security of the Borrower shall be disregarded.