I have a 1000 sq ft flat roof on a warehouse that more than 10 years ago required replacement. Closed cell foam was applied as an alternative to the usual hot tar or bitumen. Spray foam saved removing the old roof and creates a seamless, durable and energy efficient barrier right on top of the existing roof. The foam is finish coated with a roll-on membrane product to protect the foam primarily from sun damage. This top coat must be refreshed every 10 - 15 years depending on exposure. I've been totally happy with the roof the entire 10 years, but as it is an unshaded south east facing roof and the sun beats down on it, it was time to re-coat. There was also a small 10 sq. ft. repair next to a skylight where water had got under the foam. I found Foam Comfort to do the repair and re-coat as the company that had done the original install was no longer in business. Ariel and the Foam Comfort crew were exceptional from start to finish. They quickly diagnosed and tidily removed the damaged foam, re-sprayed new foam and then applied 2 coats of a newer formulation membrane that is bright white to improve heat absorption on the roof. They guarantee their work, but Im totally confident it was done right and Ill get even more years out of this coating than the original. I highly recommend Foam Comfort and I highly recommend spray foam as an alternative to the traditional flat roofing methods.