Exhibit 5.1
                      [LETTERHEAD OF ROGERS & WELLS LLP]
 
                                                                 March 16, 1999
 
Armstrong World Industries, Inc.
2500 Columbia Avenue
Lancaster, PA 17603
 
  Re:  Registration on Form S-3 of $1,000,000,000 of Debt Securities,
       Common Stock, Preferred Stock, Warrants and Depositary Shares
 
Dear Ladies and Gentlemen:
 
   We are acting as counsel to Armstrong World Industries, Inc., a
Pennsylvania corporation (the "Company"), in connection with the preparation
and filing of the Company's Registration Statement on Form S-3 (as the same
may be amended and supplemented from time to time, the "Registration
Statement") with the Securities and Exchange Commission (the "Commission")
under the Securities Act of 1933, as amended (the "Securities Act"), covering
the offer and sale by the Company from time to time of up to $1,000,000,000
aggregate amount of the following securities: (i) unsecured debt securities
which may be either senior or subordinated debt securities in one or more
series (the "Debt Securities"), which, in each case are to be issued under
Indentures (each an "Indenture" and together, the "Indentures") entered into
between the Company and The First National Bank of Chicago, as trustee
thereunder (the "Trustee"); (ii) shares of common stock, par value $1.00 per
share (the "Common Stock"), with Preferred Stock Purchase Rights attached to
each share of Common Stock (the "Rights"); (iii) shares of the Company's Class
A Preferred Stock , no par value per share (the "Preferred Stock"), in one or
more series, which may also be issued in the form of depositary shares (the
"Depositary Shares") evidenced by depositary receipts (the "Receipts"); and
(iv) warrants or other rights to purchase Debt Securities, Common Stock or
Preferred Stock (the "Warrants"). The Debt Securities, Common Stock, Preferred
Stock, Depositary Shares and Warrants are collectively referred to herein as
the "Securities." Except as otherwise defined herein, capitalized terms have
the meanings provided in the Registration Statement. The Registration
Statement provides that the Securities may be offered separately or together,
in separate series, in amounts, at prices and on terms to be set forth in one
or more supplements to the prospectus (each, a "Prospectus Supplement").
 
   We have examined such documents, records, and matters of law as we have
deemed necessary for purposes of this opinion. Based on such examination of
law as we have deemed necessary, and on the assumptions set forth below, we
are of the opinion that:
 
   1. The Debt Securities, when (a) duly executed by the Company and
      authenticated by the Trustee in accordance with the provisions of the
      applicable Indenture and issued and sold (x) in accordance with the
      Registration Statement and applicable Prospectus Supplement or (y)
      upon exercise of Warrants as contemplated by the Registration
      Statement and the applicable Prospectus Supplement, and (b) delivered
      to the purchaser or purchasers thereof against receipt by the Company
      of such lawful consideration therefor as the Company's Board of
      Directors (or a duly authorized committee thereof or a duly authorized
      officer of the Company) may determine, will be valid and binding
      obligations of the Company enforceable against the Company in
      accordance with their respective terms and entitled to the benefits of
      the applicable Indenture, subject to (i) the effect of any applicable

 
      bankruptcy, insolvency, fraudulent transfers, reorganization,
      moratorium or similar laws affecting creditors' rights generally and
      (ii) the effect of general principles of equity (regardless of whether
      considered in a proceeding at law or in equity).
 
   2. The Common Stock with the attached Rights, when (a) duly issued and
      sold in accordance with the Registration Statement and the applicable
      Prospectus Supplement or upon conversion of Debt Securities or
      Preferred Stock, or upon exercise of Warrants as contemplated by the
      Registration Statement and the applicable Prospectus Supplement and
      (b) delivered to the purchaser or purchasers thereof against receipt
      by the Company of such lawful consideration therefor as the Company's
      Board of Directors (or a duly authorized committee thereof or a duly
      authorized officer of the Company) may determine of at least the par
      value thereof, will be validly issued, fully paid and nonassessable.
 
   3. The Preferred Stock, when (a) (i) duly issued and sold in accordance
      with the Registration Statement and applicable Prospectus Supplement
      or upon conversion of Debt Securities, or upon exercise of Warrants as
      contemplated by the Registration Statement and the applicable
      Prospectus Supplement, and (ii) delivered to the purchaser or
      purchasers thereof against receipt by the Company of such lawful
      consideration therefor as the Company's Board of Directors (or a duly
      authorized committee thereof or a duly authorized officer of the
      Company) may determine or (b) duly issued pursuant to the exchange of
      validly issued and fully paid Depositary Shares in accordance with the
      terms of the applicable and valid and binding deposit agreement, will
      be validly issued, fully paid and non-assessable.
 
   4. The Warrants, when (a) duly issued and sold in accordance with the
      Registration Statement and the applicable Prospectus Supplement and
      the provisions of the applicable and valid and binding warrant
      agreement, and (b) delivered to the purchaser or purchasers thereof
      against receipt by the Company of such lawful consideration therefor
      as the Company's Board of Directors (or a duly authorized committee
      thereof or a duly authorized officer of the Company) may determine,
      will be validly issued, fully paid and non-assessable.
 
   5. The Depositary Shares, when (a) duly issued and sold in accordance
      with the Registration Statement and the applicable Prospectus
      Supplement, and (b) the Receipts in the form contemplated and
      authorized by a valid and binding deposit agreement have been duly
      executed and delivered by the depositary and delivered to the
      purchaser or purchasers thereof against receipt by the Company of such
      lawful consideration therefor as the Company's Board of Directors (or
      duly authorized committee thereof or a duly authorized officer of the
      Company) may determine, will be validly issued and will entitle the
      holders thereof to the rights specified in the Receipts and such
      deposit agreement.
 
   In rendering the foregoing opinions, we have assumed that (i) the
definitive terms of each class and series of the Securities not presently
provided for in the Registration Statement, the Company's certificate of
incorporation or certificate of designations will have been established in
accordance with all applicable provisions of law, the Indenture, the Company's
certificate of incorporation or certificate of designations and by-laws, and
the authorizing resolutions of the Company's Board of Directors, and reflected
in appropriate documentation approved by us and, if applicable, duly executed
and delivered by the Company and any other appropriate party, (ii) the
interest rate on the Debt Securities will not be higher than the maximum
lawful rate permitted from time to time under applicable law, (iii) any
 
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Securities consisting of Common Stock, Preferred Stock or Depositary Shares,
and any Common Stock, Preferred Stock or Depositary Shares for or into which
any other Securities are exercisable, exchangeable or convertible will have
been duly authorized and reserved for issuance, (iv) each warrant agreement
and deposit agreement will have been duly authorized, executed and delivered
by, and will constitute a valid and binding obligation of, each party thereto,
(v) the Indentures will be duly qualified under the Trust Indenture Act of
1939, (vi) the Registration Statement, and any amendments thereto, will have
become and at the time of issuance of the Securities will continue to be
effective, (vii) a Prospectus Supplement describing each class or series of
Securities offered pursuant to the Registration Statement will have been filed
with the Commission, (viii) the resolutions authorizing the Company to
register, offer, sell, and issue the Securities will remain in effect and
unchanged at all times during which the Securities are offered, sold, or
issued by the Company and (ix) all Securities will be issued in compliance
with applicable federal and state securities laws.
 
   In rendering the foregoing opinions, we have relied as to certain factual
matters upon certificates of officers of the Company, and we have not
independently verified the accuracy of the statements contained therein. In
rendering the foregoing opinions, our examination of matters of law has been
limited to the laws of the State of New York, the Commonwealth of Pennsylvania
and the federal laws of the United States of America, as in effect on the date
hereof. To the extent that any opinions set forth herein are dependent on the
laws of the Commonwealth of Pennsylvania we have relied on the opinion of
Douglas S. Brossman, the Senior Attorney of the Company, dated the date
hereof. Our opinion, to the extent based upon such reliance, is limited by the
qualifications, assumptions and conditions set forth in such opinion in
addition to those set forth herein.
 
   We understand that prior to offering for sale any Securities you will
advise us in writing of the terms of such offering and of such Securities,
will afford us an opportunity to review the operative documents (including the
applicable Prospectus Supplement and any applicable Underwriting Agreement,
Warrant Agreement, Deposit Agreement, Indenture or Supplemental Indenture)
pursuant to which the Securities are to be offered, sold, and issued, and will
file as an exhibit to the Registration Statement such supplement or amendment
to this opinion (if any) as we may reasonably consider necessary or
appropriate by reason of the terms of such Securities or any changes in the
Company's capital structure or other pertinent circumstances.
 
   We hereby consent to the filing of this opinion as Exhibit 5.1 to the
Registration Statement and to the reference to us in the Prospectus under the
caption "Legal Matters." In giving this consent, we do not admit that we are
within the category of persons whose consent is required under Section 7 of
the Securities Act, or the Rules and Regulations of the Commission thereunder.
 
                                          Very truly yours,
 
                                          /s/ Rogers & Wells LLP
 
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