Exhibit No. 21

Subsidiaries of Armstrong World Industries, Inc.

As of December 31, 2011

The following is a list of subsidiaries of Armstrong World Industries, Inc., omitting certain subsidiaries, which, considered in the aggregate as a single subsidiary, would not constitute a significant subsidiary.

U.S. Subsidiaries	Jurisdiction of Incorporation
Armstrong Cork Finance LLC	Delaware
Armstrong NW LLC	Delaware
Armstrong Hardwood Flooring Company	Tennessee
Armstrong Realty Group, Inc.	Pennsylvania
Armstrong Ventures, Inc.	Delaware
Armstrong Wood Products, Inc.	Delaware
Armstrong World Industries (Delaware) LLC	Delaware
AWI Licensing Company	Delaware
HomerWood Hardwood Flooring Company	Delaware
Patriot Flooring Supply, Inc.	Delaware
Worthington Armstrong Venture (50% owned
Delaware General Partnership)
Armstrong Receivables Company Limited	Delaware
Non-U.S. Subsidiaries	Jurisdiction of Incorporation
Armstrong (U.K.) Investments	United Kingdom
Armstrong Architectural Products S.L.	Spain
Armstrong Building Products B.V.	Netherlands
Armstrong Building Products Company (Shanghai) Ltd.	PRC
Armstrong Building Products GmbH	Germany
Armstrong DLW AG	Germany
Armstrong DLW Licensing GmbH	Germany
Armstrong Metal Ceilings Limited	United Kingdom
Armstrong Metalldecken AG	Switzerland
Armstrong Metalldecken GmbH	Austria
Armstrong Metalldecken Holdings AG	Switzerland
Armstrong World Industries (Australia) Pty. Ltd.	Australia
Armstrong World Industries AB	Sweden
Armstrong World Industries Canada Ltd.	Canada
Armstrong World Industries Holding GmbH	Germany
Armstrong World Industries Ltd.	United Kingdom