Protected Membrane Roof Building Science

The pmr system places the insulation on top of the mem brane protecting the roofing.

Protected membrane roof building science. A conventional roof system. Soviet era protected membrane roof pmr. A conventional roof places the membrane on top of the insulation leaving the mem brane vulnerable to extreme temperature changes freeze thaw conditions and physical abuse from heavy foot traffic figure 1. By overlaying the membrane with opaque ballast and thermal insulation the membrane is protected against accelerated oxidation evaporation of volatile oils ultraviolet degradation of organic materials such as bitumen thermal movement expansion and contraction blistering ridging and stress concentration over insulation joints.

This insulation can be placed above the roof membrane protecting the membrane from elements while continuing to deliver thermal efficiency. Fully adhered alas directly on the structural deck and the thermal control layer and ballast are located above. Clear protected membrane roof system pmr the dow styrofoam extruded polystyrene insulation is placed above the waterproof membrane to protect the membrane from the harsh rooftop environment. Protected membrane roofing insulation technology has evolved over the decades and some types like rigid extruded polystyrene foam xps is highly water resistant.

Membrane roofing is a roof system that creates a continuous watertight covering to protect the interior of a building. Membrane roofs are predominately used as a flat roofing system since they are watertight which is critical where water is not shed immediately.