Thermoplastic Membrane Roofing

Use this CSI 3 part SimpleSpecs™ master specification to specify rigid roof insulation, thermoplastic roofing membrane, and related flashings.

Roofing consists of a single ply of roofing membrane, typically plasticized polyvinyl chloride (PVC) or thermoplastic polyolefin (TPO), with or without integral mesh reinforcement. Thermoplastic membranes are characterized by their ability to be heat welded using hot air guns. Other types of membrane are also available and can be added to this section.

Roofing can be installed by using adhesive (fully adhered) or by mechanically fastening using attachment plates. They are often installed over a cover board to provide protection against hail and foot traffic and for enhanced fire protection.

The ability of a roof to withstand high winds and resulting wind uplift is directly affected by the roof systems construction and attachment. Organizations such as Factory Mutual (FM) and Underwriters Laboratories (UL) rate roof systems for wind resistance. While FM is an insurer and therefore places requirements on more than just the insulation attachment, their ratings can be used as a guide for the roofing system.

Roof insulation is available in many forms, the most common of which are included in this section.

The R-value of any insulation that uses a blowing agent, in this case polyisocyanurate and extruded polystyrene, decreases after the insulation is manufactured. Consequently, the R-value for this type of insulation is rated by LTTR – Long Term Thermal Resistance, typically measured 5 years after manufacture.

For assistance in selecting and detailing thermoplastic membrane roofing refer to the National Roofing Contractors Association (NRCA) Roofing Manual: Membrane Roof Systems, available from NRCA at www.nrca.net.

Related SimpleSpecs™ master specifications:

07 51 13 – Built-Up Asphalt Roofing 

07 52 00 – Modified Bituminous Membrane Roofing

07 56 00 – Fluid-Applied Roofing

07 65 00 – Flexible Flashings

07 72 00 – Roof Accessories 

07 72 23 – Roof Vents

07 72 33 – Roof Hatches

07 72 36 – Smoke Vents

Thermoplastic Membrane Roofing assembly example