Low Slope Roofing

Roof systems and materials generally are divided into generic classifications: low slope and steep slope. Low slope roofing includes water impermeable, or weatherproof, types of roof membranes installed on slopes less than or equal to 3:12 (14 degrees). Steep slope roofing includes watershedding types of roof coverings installed on slopes exceeding 3:12 (14 degrees).

Low slope roofing assemblies are composed of three interrelated components: the roof membrane, the roof insulation, and the roof deck itself. There are five generic classifications of low slope roof membranes or systems. Click on a roof system for more information.

• Built-up roof (BUR) membranes
• Metal panel roof systems for low-slope applications
• Polymer-modified bitumen sheet membranes
• Single-ply membranes
  • Thermoplastic membranes (e.g., PVC, TPO)
  • Thermoset membranes (e.g., EPDM)

Spray polyurethane foam-based (SPF) roof systems