Built-up Roof Membranes
Built-up roof (BUR) membranes are composed of layers of bitumen, asphalt or coal tar, or cold-applied adhesive that serves as the weatherproofing component of the membranes. Piles of reinforcement fabric, such as organic felt, which was once  cotton- or "rag-" based and now is predominantly cellulose-based glass fiber ply sheet or polyester fabric, are installed between each layer of bitumen or cold-applied adhesive. Bituminous membranes are installed in multiple-ply configurations, with bitumen or cold-applied adhesive between layers or piles of reinforcing fabric to compose the "built-up membrane.   
   

Manufactuers

		http://www.gaf.com
		http://www.certainteed.com
		http://www.conglas.com
		http://www.tamko.com
		http://www.malarkey-rfg.com
		http://www.usply.com
		http://www.firestonebpco.com
		http://www.henry.com