We are pleased to announce the availability of an updated Foam-Control Roofing Technical Bulletin No. 3001.
The National Roof Contractors Association (NRCA) has published a new recommendation for the R-value of polyisocyanurate (polyiso) insulation with the publication of updates to the 2015 The NRCA Roofing Manual: Membrane Roof Systems.
The new NRCA recommendation for polyiso R-value is based upon testing by NRCA on current generation polyiso roof insulations.
The new NRCA polyiso R-value recommendation is:
Polyiso R-value = 5.0 per inch thickness in all climate conditions.