X0306 4 2013-12-31 0 0000007431 ARMSTRONG WORLD INDUSTRIES INC AWI 0001192868 ESPE MATTHEW J C/O ARMSTRONG WORLD INDUSTRIES, INC. 2500 COLUMBIA AVENUE LANCASTER PA 17603 1 1 0 0 President and CEO Common Stock 2013-12-31 4 A 0 19979 0.00 A 50612 D Common Stock 2013-12-31 4 D 0 9209 57.61 D 41403 D Represents the number of shares acquired by the Reporting Person upon the achievement of certain share price related performance conditions and time based vesting requirements underlying a grant of performance restricted stock units (PRSUs) to the Reporting Person in an aggregate of 39,958 in August 2010 under the Issuer's 2006 Long Term Incentive Plan. Under the terms of the grant, the vesting terms of the PRSUs are as follows: (1) 50% on December 31, 2012 if the Issuer's closing stock price is at/above $42.73 for 15 days in a 20 day consecutive trading period and (2) 50% on December 31, 2013 if the Issuer's closing stock price is above/at $49.56 for 15 days in a 20 day consecutive trading period. The conditions under (1) were previously satisfied and the underlying award was reported on a Form 4 filed with the Commission on January 3, 2013. The conditions under (2) have been satisfied and the underlying award is reported herein. Represents the number of shares withheld by the Issuer to satisfy the Reporting Person's tax obligations upon the vesting of the PRSUs defined in Footnote 1 above. /s/Christopher S. Parisi, Attorney-in-fact 2014-01-02