I am writing in support of NRCA's position on polyisocyanurate insulation's thermal-resistance values as explained in "Comparing polyiso R-values," April issue, page 61.
For submittals, my current specifications require a sample of the insulation board being furnished to a project. This is not strictly done. The most recent submittal I received offered the material's label but was datedin small print1999.
I also require manufacturers to state the name or names of their products' principal blowing agents. I recently have received a manufacturer's letter indicating generic words of no meaningful value and have required three resubmittals with no improvement. It is clear the information never will arrive. I have advised the contractor to save representative samples with packaging labels and furnish them for reference if necessary. I recommend all purchasers of new products save all wrappers from every lot or truck with a matching material sample.
My conversations with people in the industry indicate the following: