FORM 11-K
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D. C. 20549

(Mark One)
[X]  ANNUAL REPORT PURSUANT TO SECTION 15(D) OF THE SECURITIES EXCHANGE ACT OF
     1934
                  For the fiscal year ended December 31, 1999

                                      OR

[ ]  TRANSITION REPORT PURSUANT TO SECTION 15(D) OF THE SECURITIES EXCHANGE
     ACT OF 1934

              For the transition period from _______ to _________

                         Commission file number 1-2116



                HARTCO FLOORING COMPANY RETIREMENT SAVINGS PLAN
                           (Full title of the Plan)



                       ARMSTRONG WORLD INDUSTRIES, INC.
              2500 Columbia Avenue Lancaster, Pennsylvania 17604
          (Name of issuer of the securities held pursuant to the Plan
              and the address of its principal executive office)

                                       1


                                                                      Page No.
                                                                      --------

Item 1. Independent Auditors' Report                                         4
        ----------------------------

Item 2. Statements of Net Assets Available for Benefits                      5
        -----------------------------------------------
             December 31, 1999 and 1998

Item 3. Statements of Changes in Net Assets Available for Benefits           6
        ----------------------------------------------------------
        Years ended December 31, 1999 and 1998

Notes to Financial Statements                                             7-13

Schedule of Assets Held for Investment Purposes                             14

Exhibits                                                                    15
- --------
        Consent of Independent Auditors

                                       2


                                   SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the members
of the committee constituting the administrator which administers the plan have
duly caused this annual report to be signed by the undersigned hereunto duly
authorized.

                       HARTCO FLOORING COMPANY
                       RETIREMENT SAVINGS PLAN

June 26, 2000          By: /s/: Jennifer E. Wisdom
                       ---------------------------
                       Jennifer E. Wisdom Vice President Human Resources

                                       3


                         Independent Auditors' Report


To the Retirement Committee of the
 Hartco Flooring Company
 Retirement Savings Plan:


We have audited the accompanying statements of net assets available for benefits
of the Hartco Flooring Company Retirement Savings Plan as of December 31, 1999
and 1998, and the related statements of changes in net assets available for
benefits for the years then ended. These financial statements are the
responsibility of the Plan's management. Our responsibility is to express an
opinion on these financial statements based on our audits.

We conducted our audits in accordance with generally accepted auditing
standards.  Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement.  An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements.  An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in
all material respects, the net assets available for benefits of the Hartco
Flooring Company Retirement Savings Plan as of December 31, 1999 and 1998, and
the changes in net assets available for benefits for the years then ended in
conformity with generally accepted accounting principles.

Our audits were performed for the purpose of forming an opinion on the basic
financial statements taken as a whole.  The supplemental schedule of assets held
for investment purposes is presented for the purpose of additional analysis and
is not a required part of the basic financial statements but is supplementary
information required by the Department of Labor's Rules and Regulations for
Reporting and Disclosure under the Employee Retirement Income Security Act of
1974.  The supplemental schedule has been subjected to the auditing procedures
applied in the audits of the basic financial statements and, in our opinion, is
fairly stated in all material respects in relation to the basic financial
statements taken as a whole.

KPMG LLP
Dallas, Texas
June 16, 2000

                                       4


                            HARTCO FLOORING COMPANY
                            RETIREMENT SAVINGS PLAN

                Statements of Net Assets Available for Benefits

                          December 31, 1999 and 1998



                                                                   1999                 1998
                                                            ------------------       -----------
                                                                               
Assets:
    Investments, at fair value (note 5):
       Armstrong Holdings, Inc. common stock               $           56,257        $         -
       Fidelity Magellan Fund                                       1,941,949          1,501,323
       Fidelity Equity Income Fund                                  1,516,877          1,658,729
       Fidelity Intermediate Bond Fund                                980,972          1,154,431
       Fidelity Overseas Fund                                         575,744            441,761
       Fidelity Asset Manager Fund                                    215,799            166,944
       Fidelity Retirement Money Market Fund                        1,043,205            480,202
       Participant loans                                              264,984            234,490
                                                            ------------------       ------------
             Total investments                                      6,595,787          5,637,880

    Receivables (note 2):
       Employer contributions                                               -            244,123
       Employee contributions                                           2,674                  -
       Other                                                           34,098                  -
                                                             -----------------       ------------
             Total receivables                                         36,772            244,123
                                                             -----------------       ------------
             Total assets                                           6,632,559          5,882,003
                                                             -----------------       ------------
Net assets available for benefits                            $      6,632,559        $ 5,882,003
                                                             =================       ============


See accompanying notes to financial statements.

                                       5


                            HARTCO FLOORING COMPANY
                            RETIREMENT SAVINGS PLAN

          Statements of Changes in Net Assets Available for Benefits

                    Years ended December 31, 1999 and 1998




                                                                                       1999                 1998
                                                                                ------------------     --------------
                                                                                                 
Additions to net assets attributed to:
    Investment income:
       Interest and dividend income                                            $          498,432      $     309,489
       Net appreciation in fair value of investments (note 5)                             235,315            421,079
                                                                                ------------------     --------------
                Net investment income                                                     733,747            730,568

    Contributions:
       Participant (note 2)                                                               379,718            400,678
       Employer (note 2)                                                                   50,795            299,765
       Rollovers (note 3)                                                                   4,074             15,423
                                                                                ------------------     --------------
                Total contributions                                                       434,587            715,866
                                                                                ------------------     --------------
                Total additions                                                         1,168,334          1,446,434
                                                                                ------------------     --------------
Deductions from net assets attributed to - benefits paid
    to participants (notes 2 and 3)                                                     (417,778)          (628,893)

                Net increase                                                              750,556            817,541

Net assets available for benefits at the beginning of the year                          5,882,003          5,064,462
                                                                               -------------------     --------------
Net assets available for benefits at the end of the year                       $        6,632,559      $   5,882,003
                                                                               ===================     ==============

See accompanying notes to financial statements.

                                       6


                            HARTCO FLOORING COMPANY
                            RETIREMENT SAVINGS PLAN

                         Notes to Financial Statements

                          December 31, 1999 and 1998


(1)  General Information

     On June 28, 1996, Triangle Pacific Corp. (the Company) acquired from
     Premark all of the common stock of Hartco Flooring Company. In connection
     with this acquisition, Premark and the Company agreed to spin off,
     effective as of June 28, 1996, that portion of the Premark Plan benefiting
     participants who were employees or former employees of Premark, to a
     separate plan sponsored and maintained by the Company to be known as the
     Hartco Flooring Company Retirement Savings Plan (the Plan), as set forth
     herein, as a continuation, without interruption, of such portion of the
     Premark Plan.

(2)  Description of the Plan

     The following description of the Plan provides only general information.
     Participants should refer to the Plan documents for more detailed
     information.

     (a)  General

          The Plan is a defined contribution plan which provides retirement
          benefits to employees of Hartco Flooring Company, a division of
          Triangle Pacific Corp., who are not members of a collective bargaining
          agreement and whose customary employment is for at least 1,000 hours
          during a 12 month period. Employees are eligible to participate in the
          Plan on the first day of the month coincident with or following the
          completion of six months of service. All eligible employees whose
          customary employment is not for at least 1,000 hours during a year
          participate in the plan on the first day of the month coincident with
          or following the 12 month period after their employment or any plan
          year thereafter, provided 1,000 hours of service is completed during
          this time period. However, employees must not be active participants
          in any other defined contribution plan to which the Company or any
          subsidiary contributes on their behalf. The Plan is administered by
          Triangle Pacific Corp. and advised by the retirement committee
          appointed by the Board of Directors. The Plan is subject to the
          provisions of the Employee Retirement Income Security Act of 1974
          (ERISA).

   (b)    Contributions

          Participants are permitted to contribute from 1% to 16% of their
          eligible compensation to the Plan, as defined by the Plan documents.
          Participants may elect to invest their contributions in any of the
          available investment funds offered by Fidelity Management Trust
          Company, the Trustee. The Company will provide a 25% match of active
          participant's contributions, up to 4% of the participant's eligible
          compensation.

          Effective January 1, 1998, the Plan was amended to include a profit
          sharing component. The Company may contribute a discretionary profit
          sharing amount based solely at the discretion of the Board of
          Directors of the Company.

                                       7


                            HARTCO FLOORING COMPANY
                            RETIREMENT SAVINGS PLAN

                         Notes to Financial Statements

                          December 31, 1999 and 1998


     (c)  Participant Accounts

          Each participant's account is credited with the participant's
          contribution and an allocation of the Company's contribution, Plan
          earnings, and forfeitures of terminated participants' nonvested
          accounts. The benefit to which a participant is entitled is the
          benefit that can be provided from the participant's vested account.

     (d)  Vesting

          Participants are fully vested in the current value of their own
          contributions and earnings thereon, and become fully vested in Company
          contributions and related earnings credited to their accounts based
          upon their years of vesting service as shown in the following table:


                   Years of                                 Vested
                vesting service                           percentage
             --------------------                       --------------
                  Less than 1                                  0%
               1 but less than 2                              20
               2 but less than 3                              40
               3 but less than 4                              60
               4 but less than 5                              80
                   5 or more                                 100

          Participants who are age 65 or over or become permanently disabled are
          automatically 100% vested in the value of Company contributions and
          related earnings credited to their account.

     (e)  Investment Options

          Elective contributions may be invested in guaranteed income funds,
          fixed income funds, equity funds or a money market fund at the option
          of the participating employee. The Plan has investment options
          available to which participants may allocate their contributions
          follow:

               .  Armstrong Holdings, Inc. Common Stock - Effective April 1,
                  1999, the Plan was amended to include Armstrong Holdings, Inc.
                  common stock as one of the investment options. Armstrong
                  Holdings, Inc. (formerly Armstrong World Industries, Inc.) is
                  the parent company of Triangle Pacific Corp. (see note 6).
                  Armstrong is publicly traded on the New York Stock Exchange.

               .  Fidelity Magellan Fund - The Fidelity Magellan Fund is a
                  diversified portfolio of common stocks of domestic and foreign
                  issuers. The portfolio seeks capital appreciation by investing
                  in growth stocks, value stocks or both.


                                                                     (Continued)

                                       8


                            HARTCO FLOORING COMPANY
                            RETIREMENT SAVINGS PLAN

                         Notes to Financial Statements

                          December 31, 1999 and 1998


               .  Fidelity Equity Income Fund - The Fidelity Equity Income
                  Fund has a primary objective of seeking reasonable income
                  by investing 65% of total assets in foreign and domestic
                  income producing equity securities, such as stocks, bonds
                  and other debt securities. The fund also seeks capital
                  appreciation when consistent with its primary objective.

               .  Fidelity Intermediate Bond Fund - The Fidelity
                  Intermediate Bond Fund has a primary objective of seeking
                  high current income by investing in U.S. dollar-dominated
                  investment grade debt securities with maturities between
                  three to ten years. The Lehman Brothers Intermediate
                  Government/Corporate Bond Index is used as a guide in
                  structuring the fund and selecting the investments.

               .  Fidelity Overseas Fund - The Fidelity Overseas Fund seeks
                  long-term growth of capital by primarily investing in the
                  common stock of foreign issuers.

               .  Fidelity Asset Manager Fund - The Fidelity Asset Manager
                  Fund strives for high total return with reduced risk over
                  the long-term. The fund pursues this goal with
                  diversified investments of stocks, bonds and short-term
                  and money market instruments, both domestic and
                  international, while maintaining a diversified mix of
                  securities.

               .  Fidelity Retirement Money Market Fund - The Fidelity
                  Retirement Money Market Fund seeks to earn a high level
                  of current income while maintaining a stable $1.00 share
                  price by investing in high-quality, short- term
                  securities. These securities may include, but are not
                  limited to, high-quality short-term U.S. dollar
                  denominated money market securities, domestic and foreign
                  issuers.

     (f)  Participant Loans

          Participants may borrow from the Plan an amount greater than $1,000
          but less than 50% of the participant's vested account balance. In no
          event can the participant borrow more than $50,000. Loans are for a
          period not to exceed five years and bear interest at 1% above the
          prime rate of interest being charged by local banks at the time the
          loan is authorized. The interest rate for 1999 was 9.25%.


                                                               (Continued)

                                       9


                            HARTCO FLOORING COMPANY
                            RETIREMENT SAVINGS PLAN

                         Notes to Financial Statements

                          December 31, 1999 and 1998


     (g)  Payment of Benefits

          On termination of service due to death, disability or retirement, a
          participant may elect to receive the total value of their account
          attributable to their contributions, as well as the vested value of
          their Company contributions, in cash or by purchasing an annuity under
          the terms of an annuity contract. For termination of service due to
          other reasons, a participant may receive the value of the vested
          interest in his or her account as a lump sum distribution.
          Participants may make hardship withdrawals from their earnings
          deferred contributions at specified times, subject to the
          determination by the Plan administrator that the withdrawal is
          required to meet an immediate and heavy financial need.

     (h)  Forfeitures

          Company contributions forfeited by terminating employees are used to
          reduce future Company contributions to the Plan ($10,881 in 1999 and
          $5,247 in 1998). The Company will reinstate forfeited balances to the
          accounts of participants who rejoin the Company within five years of
          their termination.

(3)  Summary of Significant Accounting Policies

     (a)  Basis of Accounting

          The financial statements of the Plan are prepared under the accrual
          method of accounting.

     (b)  Investment Valuation and Income Recognition

          The Plan's investments are stated at fair value and have been
          determined based on closing market quotations. Purchases and sales of
          securities are recorded by the trustee at current cost on the trade
          date. Realized and unrealized gains (losses) on investments are based
          on the fair value of the assets at the beginning of the Plan year or
          at the time of purchase during the year. Interest income is recorded
          on the accrual basis. Dividends are recorded on the ex-dividend date.

     (c)  Administration Expenses

          In accordance with the provisions of the Plan, unless paid by the
          Company, all costs of administering the Plan are charged to the Plan.
          During 1999 and 1998, all significant expenses were paid by the
          Company ($18,305 in 1999 and $17,797 in 1998, respectively).

     (d)  Payment of Benefits

          Benefits are recorded when distributed.

     (e)  Rollover Contributions

          Employee rollovers represent receipts from employees receiving
          distributions from their previous employers' qualified plan(s).


                                                               (Continued)

                                       10


                            HARTCO FLOORING COMPANY
                            RETIREMENT SAVINGS PLAN

                         Notes to Financial Statements

                          December 31, 1999 and 1998


     (f)  Use of Estimates

          The preparation of financial statements in conformity with generally
          accepted accounting principles requires management to make estimates
          and assumptions that affect the reported amounts of assets,
          liabilities, and changes therein, and disclosure of contingent assets
          and liabilities. Actual results could differ from those estimates.

(4)  Units

     Participant accounts are assigned investment fund units/shares. The net
     asset value per unit/shares by fund/account for the 1999 and 1998 calendar
     quarters ended is as follows:



                                                                                                            Units at
                                                         1999 quarters ended                              December 31,
                              --------------------------------------------------------------------
                               March 31        June 30          September 30           December 31            1999
                              -----------    -----------        ------------           -----------       ------------
                                                                                          
     Armstrong Holdings,
      Inc. common stock       $     45.19    $     57.81        $      44.94           $     33.37              1,686
     Fidelity Magellan
      Fund                         129.75         129.77              122.02                136.63             14,213
     Fidelity Equity
      Income Fund                   55.92          61.63               56.03                 53.48             28,363
     Fidelity Intermediate
      Bond Fund                     10.16           9.96                9.88                  9.76            100,509
     Fidelity Overseas
      Fund                          36.99          38.88               41.11                 48.01             11,992
     Fidelity Asset
      Manager Fund                  17.54          18.08               17.28                 18.38             11,741
     Fidelity Retirement
      Money Market Fund              1.00           1.00                1.00                  1.00          1,043,205





                                                                                                    Units at
                                                  1998 quarters ended                              December 31,
                              ---------------------------------------------------------------
                                March 31         June 30      September 30      December 31           1998
                              -------------     ---------     ------------    ---------------      ------------
                                                                                    
     Fidelity Magellan
      Fund                    $      108.81     $  109.63     $      97.52    $        120.82            12,426
     Fidelity Equity
      Income Fund                     57.51         57.20            49.60              55.55            29,860
     Fidelity Intermediate
      Bond Fund                       10.17         10.20            10.40              10.27           112,408
     Fidelity Overseas
      Fund                            37.09         37.70            31.14              35.98            12,278
     Fidelity Asset
      Manager Fund                    19.59         19.54            18.24              17.39             9,600
     Fidelity Retirement
      Money Market Fund                1.00          1.00             1.00               1.00           480,202


                                                                     (Continued)

                                       11


                           HARTCO FLOORING COMPANY
                           RETIREMENT SAVINGS PLAN

                        Notes to Financial Statements

                          December 31, 1999 and 1998

(5)  Investments

     In September 1999, the American Institute of Certified Public Accountants
     Issued Statement of Position 99-3, Accounting for and Reporting of Certain
     Defined Contribution Plan Investments and Other Disclosure Matters (SOP 99
     SOP 99-3 simplifies the disclosure for certain investments and is effective
     for plan years ending after December 15, 1999. The Plan adopted SOP 99-3
     during the Plan year ending December 31, 1999. Accordingly, information
     previously required to be disclosed about participant directed fund
     investment programs is not presented in the Plan's 1999 financial
     statements. The Plan's 1998 financial statements have been reclassified to
     conform with the current year's presentation.

     The following investments exceed 5% of the Plan's net assets available for
     Plan benefits at December 31, 1999 and 1998:

                                                              Fair value
                                                       ------------------------
                                                           1999         1998
                                                       -----------  -----------

          Fidelity Magellan Fund                       $ 1,941,949  $ 1,501,323
          Fidelity Equity Income Fund                    1,516,877    1,658,729
          Fidelity Intermediate Bond Fund                  980,972    1,154,431
          Fidelity Overseas Fund                           575,744      441,761
          Fidelity Retirement Money Market Fund          1,043,205      480,202
          Other - less than 5%                             537,040      401,434
                                                       -----------  -----------
             Total investments                         $ 6,595,787  $ 5,637,880
                                                       ===========  ===========

     During 1999 and 1998, the Plan's investments had net realized and
     unrealized gains (losses) as follows:

                                                        1999          1998
                                                     ----------    ----------

          Armstrong Holdings, Inc. common stock      $ (23,081)    $      --
          Triangle Pacific Corp. common stock               --         7,899
          Fidelity Magellan Fund                       204,771       246,845
          Fidelity Equity Income Fund                  (43,380)      125,163
          Fidelity Intermediate Bond Fund              (51,714)        7,436
          Fidelity Overseas Fund                       137,637        43,096
          Fidelity Asset Manager Fund                   11,082        (9,360
                                                     ---------     ---------
                Net appreciation in fair value of
                  investments                        $ 235,315     $ 421,079
                                                     =========     =========

                                                                     (Continued)

                                       12


                           HARTCO FLOORING COMPANY
                           RETIREMENT SAVINGS PLAN

                        Notes to Financial Statements

                          December 31, 1999 and 1998

     The components of investment income for the years ended  December 31, 1999
     and 1998 are as follows:



                                                              1999           1998
                                                           ----------     ----------
                                                                    
     Investment income:
      Interest and dividend income                         $  498,432     $  309,489
      Net appreciation in fair value of investments           235,315        421,079
                                                           ----------     ----------
                                                           $  733,747     $  730,568
                                                           ==========     ==========


(6)  Acquisition

     On July 22, 1998, Triangle Pacific Corp. was acquired by Armstrong World
     Industries, Inc. (a subsidiary of Armstrong Holdings, Inc.). The Board of
     Directors of Triangle Pacific Corp. intends to continue providing
     retirement benefits through the Company's defined contribution plans.

(7)  Tax Status of the Plan

     The Internal Revenue Service has determined and informed the Company by a
     letter dated January 27, 1998, that the Plan and related trust are designed
     in accordance with applicable requirements of the Internal Revenue Code
     (IRC). The Plan has been amended since receiving the determination letter.
     However, the Plan administrator and Plan's management believe that the Plan
     is designed and is currently being operated in compliance with the
     applicable requirements of the IRC.

(8)  Plan Termination

     Although it has not expressed intent to do so, the Company has the right to
     discontinue its contribution at any time and to terminate the Plan subject
     to the provision of ERISA. In the event of Plan termination, participants
     will become fully vested in their accounts.

(9)  Related Party Transactions

     Certain Plan investments are shares of common stock of Armstrong Holdings,
     Inc. and shares of mutual funds managed by Fidelity Investments. Triangle
     Pacific Corp. is a wholly-owned subsidiary of Armstrong Holdings, Inc.
     Fidelity Management Trust Company is the trustee as defined by the Plan.
     Therefore, transactions involving these entities or funds qualify as party-
     in-interest transactions.

(10) Subsequent Events

     Effective January 1, 2000, the Plan was amended to increase the employer
     matching contribution percentage to 50% of qualified employee contributions
     up to 6% of the employee's annual earnings for all participants.



                                       13


                                                                      Schedule 1


                             HARTCO FLOORING COMPANY
                             RETIREMENT SAVINGS PLAN

                Schedule of Assets Held for Investment Purposes
                       at end of year December 31, 1999




                                                                                                 Current
    Identity of issuer                          Description of investment                          value
- -----------------------------          --------------------------------------              ----------------
                                                                                    
Armstrong Holdings, Inc.*              Common stock                                       $         56,257

Fidelity Investments*                  Fidelity Magellan Fund                                    1,941,949

Fidelity Investments*                  Fidelity Equity Income Fund                               1,516,877

Fidelity Investments*                  Fidelity Intermediate Bond Fund                             980,972

Fidelity Investments*                  Fidelity Overseas Fund                                      575,744

Fidelity Investments*                  Fidelity Asset Manager Fund                                 215,799

Fidelity Investments*                  Fidelity Retirement Money Market Fund                     1,043,205

Participant loans*                     Loans to participants                                       264,984
                                                                                           ----------------
                                               Total investments                          $      6,595,787
                                                                                           ================


* Party-in-interest

See accompanying independent auditors' report.

                                       14