The two most common types of flat roof membranes are EPDM and PVC. While modified bitumen is also still used, most owners are moving away from asphalt based products due to the environmental and health hazards.Fully adhered membranes have a higher cost, but are less prone to damage and leaks. Generally, the insulation or roofing board is mechanically fastened to the structure and then the roof membrane is adhered to create a full assembly that resists uplift. Fully adhered membranes can also be installed directly to concrete or wood substrates.
