Use this 3 part SimpleSpecs™ master specification to specify roof insulation that is not part of a roofing assembly, such as under metal roof panels.
This section is intended to be used to specify insulation that is not part of a roofing assembly, such as under metal roof panels. Roof insulation in built-up and single ply roof assemblies is typically specified along with the roofing as a single assembly.
Insulation is available in many forms, the most common of which are included in this section.
The ability of a roof to withstand high winds and resulting wind uplift is directly affected by insulation 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 insulation attachment.
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.
Insulation in built-up and single ply roofs is typically specified along with the roofing as a single assembly.
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.