X0306 4 2016-04-11 0 0000007431 ARMSTRONG WORLD INDUSTRIES INC AWI 0001208356 GAFFNEY JAMES J C/O ARMSTRONG WORLD INDUSTRIES, INC. 2500 COLUMBIA AVENUE, P.O. BOX 3001 LANCASTER PA 17603 1 0 0 0 Common Stock 21965 D Includes vested restricted stock units and 2,197 unvested units granted on July 13, 2015, as well as units not yet acquirable by the Director, granted as part of the Issuer's nonemployee Director Compensation Program under the terms of the 2008 Directors Stock Unit Plan, as amended. Under the Plan, the units vest (contingent upon the Director's continued service as of such date) on the earlier of (i) the one-year anniversary of the grant; (ii) the death or total and permanent disability of the Director; or (iii) the date of any Change in Control Event (as defined in the Plan). Vested units will be acquirable by the Director (x) for those restricted stock units granted prior to June 2011, six (6) months following the termination of the Director's service on the Issuer's Board of Directors, and, (y) for those units granted during and after June 2011, at the time of the termination of the Director's service on the Issuer's Board of Directors. NOTE: All restricted stock units on Table I have been adjusted as a result of the spin-off of Armstrong Flooring, Inc., effective on April 1, 2016. /s/ Mark A. Hershey, Attorney-in-Fact 2016-04-13