Single-ply membranes are factory-manufactured sheet membranes. They generally are
categorized as either thermoplastic or thermoset. Thermoplastic materials can be
repeatedly softened when heated and hardened when cooled. Thermoset materials solidify,
or "set," irreversibly after heating. Single ply membranes commonly are referred
to by their chemical acronyms, such as ethylene propylene diene terpolymer (EPDM).
Single-ply sheet membranes are produced using one of three manufacturing processes:
calendering, extruding or spread coating. The membranes may contain reinforcement
layers. Common reinforcements for single ply membranes include polyester fabrics
or scrims, glass fiber, or a felt or fleece backing.
A finished sheet's thickness typically is referred to as mil thickness; 1 mil equals
0.001 inch. Common mil thicknesses for these sheet membranes range from 30 mils
to 60 mils.
Single-ply membranes can be installed fully adhered, mechanically attached or held
down with ballast. Most single-ply roof systems do not receive surfacings.
In many instances, a combination of attachment methods are used to secure a roof
system. For instance, an insulation may be mechanically attached to the substrate
with the roof membrane fully adhered to the insulation.
to learn more about thermoplastic
membranes, such as polyvinyl chloride (PVC) and thermoplastic olefin (TPO).
to learn more about thermoset
membranes, such as ethylene propylene diene terpolymer (EPDM).