This is thick roof sealant used to seal metal roofs on mobile homes, out buildings and barns, sealing around air conditioning units and vents, etc.. It sticks to everything so it can be used on shingles (wood or asphalt) or any other building material. It is usually rolled on like a thick paint or mopped on. This is surplus material currently being sold to roofing companies in bulk 55 gal drums at huge savings. We got our hands on some to pass the savings onto those of you out there that like to save money and do it themselves. We used it on our main building here. Drum mixing is accomplished by using a long shaft "mud" mixer blade (we bought ours from Harbor Freight Tools and welded a longer shaft on it). Comparable product at Home Depot is over $76.00/4.75 gallons. If you are a roofer, buy it in bulk while it lasts! 55 gallon drums must be shipped by motor freight. Call for a shipping quote. NOTE: As surplus, we cannot guarantee finish color. It is usually silver but we have seen off-tints as well.