X0303 4 2011-03-25 0 0000007431 ARMSTRONG WORLD INDUSTRIES INC AWI 0001509566 Grizzle Victor 2500 COLUMBIA AVENUE LANCASTER PA 17603 0 1 0 0 Executive V.P., Armstrong Bdg Common Stock 2011-03-25 4 P 0 9000 44.20 A 10000 D This transaction was executed in multiple trades. The price reported reflects the average price per share. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer, full information regarding the number of shares and prices at which the transaction was effected. /s/ Mary J. Huwaldt, by power of attorney for Victor Grizzle 2011-03-29