X0306 4 2018-06-06 0000007431 ARMSTRONG WORLD INDUSTRIES INC AWI 0001671165 Cookson David S C/O ARMSTRONG WORLD INDUSTRIES INC. 2500 COLUMBIA AVENUE LANCASTER PA 17603 1 SVP, Americas Common Stock 2018-06-06 4 M 0 12412 37.83 A 33281 D Common Stock 2018-06-06 4 S 0 12412 63.00 D 20869 D Common Stock 2018-06-06 4 M 0 7218 45.32 A 28087 D Common Stock 2018-06-06 4 S 0 7218 63.00 D 20869 D Common Stock 2018-06-06 4 M 0 7706 47.17 A 28575 D Common Stock 2018-06-06 4 S 0 7706 63.00 D 20869 D Stock Options (Right to Buy) 37.83 2018-06-06 4 M 0 12412 0 D 2022-02-28 Common Stock 12412 0 D Stock Options (Right to Buy) 45.32 2018-06-06 4 M 0 7218 0 D 2023-02-20 Common Stock 7218 0 D Stock Options (Right to Buy) 47.17 2018-06-06 4 M 0 7706 0 D 2024-02-25 Common Stock 7706 0 D Options exercised and shares sold pursuant to a 10b5-1 Plan. The stock options were granted on February 28, 2012. Grant has a graded vesting schedule. Date Exercisable will vary for each vesting tranche. All options are currently vested and exercisable. The stock options were granted on February 20, 2013. Grant has a graded vesting schedule. Date Exercisable will vary for each vesting tranche. All options are currently vested and exercisable. The stock options were granted on February 25, 2014. Grant has a graded vesting schedule. Date Exercisable will vary for each vesting tranche. All options are currently vested and exercisable. /s/Bryan Y.M. Tham, Attorney-in-fact 2018-06-07