You may want to call one of these contractors and talk to them. They may be able to give you some ideas on materials to use and where to purchase the materials.
Flat roofs are tough.
Watewr can sneak it's way through the smallest hole and work its way to an area away from the hole. I would like to seal the whole sureface of the roof. You may want to call one of these contractors and talk to them. They may be able to give you some ideas on materials to use and where to purchase the materials. Flat roofs are tough.