GAF Materials LLC
The Dow Chemical Company
Carlisle Companies Inc.
Compagnie de Saint-Gobain
Firestone Building Products Company
LLC
3M Company
Johns Manville (Berkshire Hathaway Inc.)
Owens Corning
Akzo Nobel N.V.
Sika AG
North American Roofing Services Inc.
IcopalApS
Braas Monier Building Group
CertainTeed Corporation
E.I. du Pont de Nemours and Company (DuPont)