I got www.superiorrvroof.com. for my RV last year. I have a TPO roof. Im just waiting for the weather to stop raining and warm up to apply it. What sold me on it was that it can be applied and if it rains on it within a few hours it is fine and it is OK with standing water or pooling water if you have that on your roof, and you can do a second coat anytime within 2 weeks of the first. I called Hengs, and was told that it was not compatable with TPO roofs, and Dicor said their product was not to be used if the roof has ponding water areas