Flat Roof Membrane is installed directly over the rigid insulation. Membrane is the weatherproofing portion of the installation, and needs to be fully installed over the rigid insulation and any roof penetrations to make the building watertight. There are many different membrane products that can be used, and many different installation techniques.
Every type of membrane product used in flat roofing is unique with its own strengths and weaknesses. For more information on the most commonly used membrane products, see our pages below on:
Single Ply membrane roofs, like EPDM Membrane and TPO Membrane, can be installed a few different ways. The most commonly used membrane installation methods are:
Asphalt based products, like modified bitumen and built up roofs (BUR) have their own installation methods.
No matter what roof membrane product you use, the installation is comprised of two aspects: Field work and detail work. The field work, for the most part, is the easy portion where the membrane is installed over open, flat areas.
The detail work is the harder portion, which includes areas like HVAC units, skylights, walls, roof hatches, and other penetrations and rooftop equipment in the roof system.
Over 90% of flat roof leaks come from the detail portion of the flat roof work, so it is important to have an expert crew performing any membrane installation work.
After the membrane is fully installed, the manufacturer’s inspection and warranty award is the last part of the roof installation process. See Roof Inspection to learn about the next part of the flat roofing process.