Business	12 Months Ended
Dec. 31, 2024
Business [Abstract]
Business	NOTE 1. BUSINESS Armstrong World Industries, Inc. (“AWI”) is a Pennsylvania corporation incorporated in 1891. When we refer to “AWI,” the “Company,” “we,” “our” and “us” in these notes, we are referring to AWI and its subsidiaries. Acquisitions and Investments in Unconsolidated Affiliates In December 2024, we acquired all the issued and outstanding stock of A. Zahner Company (“Zahner”), based in Kansas City, Missouri. Zahner is a designer and manufacturer of exterior metal architectural solutions. The operations, assets and liabilities of Zahner are included in our Architectural Specialties segment. In April 2024, we acquired all the issued and outstanding membership interests in 3form, LLC (“3form”), based in Salt Lake City, Utah, from Hunter Douglas, Inc. 3form is a designer and manufacturer of architectural resin and glass products used for specialty walls, partitions and ceilings. The operations, assets and liabilities of 3form are included in our Architectural Specialties segment. In January 2024, we entered into a strategic partnership and equity investment in Overcast Innovations LLC (“Overcast”) with McKinstry Essention, LLC whereby we contributed $5.5 million in exchange for a 19.5% ownership interest in Overcast, with future rights to increase our ownership interest. Overcast is a solutions company offering prefabricated ceiling cloud systems, modular grid platforms and engineering design services to reduce waste and inefficiencies in the built environment. Our investment and equity earnings in Overcast are included in our Unallocated Corporate segment. In October 2023, we acquired a portion of the business and certain assets of Insolcorp, LLC (“Insolcorp”), based in Albemarle, North Carolina. Insolcorp develops, tests and manufactures energy saving products deployed in building and roofing installations. The acquired operations, assets and liabilities of Insolcorp are included in our Mineral Fiber segment. In July 2023, we acquired all the issued and outstanding stock of BOK Modern, LLC (“BOK”), based in San Rafael, California. BOK is a designer of exterior metal architectural solutions. The operations, assets and liabilities of BOK are included in our Architectural Specialties segment. In November 2022, we acquired the business of GC Products, Inc. (“GC Products”), based in Lincoln, California. GC Products is a designer and manufacturer of glass-reinforced-gypsum, glass-reinforced-cement, molded ceiling and specialty wall products. The operations, assets and liabilities of GC Products are included in our Architectural Specialties segment. See Note 5 for additional details.

Business

12 Months Ended

Dec. 31, 2024

NOTE 1. BUSINESS

Armstrong World Industries, Inc. (“AWI”) is a Pennsylvania corporation incorporated in 1891. When we refer to “AWI,” the “Company,” “we,” “our” and “us” in these notes, we are referring to AWI and its subsidiaries.

Acquisitions and Investments in Unconsolidated Affiliates

In December 2024, we acquired all the issued and outstanding stock of A. Zahner Company (“Zahner”), based in Kansas City, Missouri. Zahner is a designer and manufacturer of exterior metal architectural solutions. The operations, assets and liabilities of Zahner are included in our Architectural Specialties segment.

In April 2024, we acquired all the issued and outstanding membership interests in 3form, LLC (“3form”), based in Salt Lake City, Utah, from Hunter Douglas, Inc. 3form is a designer and manufacturer of architectural resin and glass products used for specialty walls, partitions and ceilings. The operations, assets and liabilities of 3form are included in our Architectural Specialties segment.

In January 2024, we entered into a strategic partnership and equity investment in Overcast Innovations LLC (“Overcast”) with McKinstry Essention, LLC whereby we contributed $5.5 million in exchange for a 19.5% ownership interest in Overcast, with future rights to increase our ownership interest. Overcast is a solutions company offering prefabricated ceiling cloud systems, modular grid platforms and engineering design services to reduce waste and inefficiencies in the built environment. Our investment and equity earnings in Overcast are included in our Unallocated Corporate segment.

In October 2023, we acquired a portion of the business and certain assets of Insolcorp, LLC (“Insolcorp”), based in Albemarle, North Carolina. Insolcorp develops, tests and manufactures energy saving products deployed in building and roofing installations. The acquired operations, assets and liabilities of Insolcorp are included in our Mineral Fiber segment.

In July 2023, we acquired all the issued and outstanding stock of BOK Modern, LLC (“BOK”), based in San Rafael, California. BOK is a designer of exterior metal architectural solutions. The operations, assets and liabilities of BOK are included in our Architectural Specialties segment.

In November 2022, we acquired the business of GC Products, Inc. (“GC Products”), based in Lincoln, California. GC Products is a designer and manufacturer of glass-reinforced-gypsum, glass-reinforced-cement, molded ceiling and specialty wall products. The operations, assets and liabilities of GC Products are included in our Architectural Specialties segment.

See Note 5 for additional details.