1. Why Polyurethane (SPF) foam roofing? Because the SPF roof is a continuous seamless insulating (R-10 at rate of 1 1/2 inch) waterproofing system that covers your whole roof without seams or joints. 2. Can you foam over my existing roof? The short answer is it depends on the type of roof and the shape it is in. There are many types of roofs out there and one of those that can not or should not be foamed over are membrane roofs (TPO) they need to be torn off. A roof system that has a silicone coating on it should never be foamed over as it will not adhere correctly. The answer is give us a call and we will inspect your roof for free and provide you with a qualified quote. 3. What is the longevity or life span of a foam roofing A roof that was sprayed correctly with 1 1/2 of foamed and coated correctly with proper maintenance can last 30 to 40 years. 4. What is the maintenance for a SPF roof? The maintenance for the roof is to once a year inspect and remove all leaves pine needles and debris off of the roof. Inspect the coating for damage and splits, Foam America will inspect your roof if needed for free if we installed it. 5. Can you spray a silicone coating over an elastomeric coated roof? Yes you can. You first must clean the existing roof properly and a silicone coating can be put on over an elastomeric coating. Can you spray an elastomeric coating over a silicone coated roof? No, you cannot get elastomeric coating to adhere to a silicone coating. “The only thing that sticks to silicone is silicone itself.” 7. Can your foam over the top of my existing foamed roof? It depends. If there is elastomeric covering your foam roof, it is said that you can spray foam over the existing roof if you spray a primer on it first.