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Certification for re-purposed polyiso. Manufacturer is unkown

pfrost99 | Posted in Building Code Questions on

The Farifax County code in which I live is as follows:

N1101.12.1 (R303.1.1) Building thermal envelope insulation.
An R-value identification mark shall be applied by the manufacturer to each piece of building thermal envelope insulation 12 inches (305 mm) or greater in width. Alternately, the insulation installers shall provide a certification listing the type, manufacturer and R-value of insulation installed in each element of the building thermal envelope. For blown or sprayed insulation (fiberglass and cellulose), the initial installed thickness, settled thickness, settled R-value, installed density, coverage area and number of bags installed shall be listed on the certification. For sprayed polyurethane foam (SPF) insulation, the installed thickness of the areas covered and R-value of installed thickness shall be listed on the certification. The insulation installer shall sign, date and post the certification in a conspicuous location on the job site.

My question’s:
1. Is there a general certification that exists that I can use that says the R-Value for Polyiso?
Problem: I cant find a manufacturer name on the product or an R-value. There is some labeling, but I was not able to find the manufacturer when searching. The labeling on the polyiso is CHE 04136.

2. Without a manufacturer name or R-value can I still use this re-purposed polyiso? If so, how do I get round the IC code requirements properly?
Not trying to pull wool over the inspetcors eye’s. I just want to do the right thing, but it has become a difficult speed bump and I may have to trash the whole idea.
Please help if anyone has a good suggestion, I am open for ideas, solutions.

Note: I would be the installer as the home owner. Also the key word I’m reading in the ICC code is: ALTERNATELY, the insulation installer shall……….

Thank you,



  1. Expert Member
    Dana Dorsett | | #1

    If the assembly meets code prescription without adding in the R-value of the polyiso, does it really matter?

    In general terms, there is no polyiso product I'm aware of that tests less than R5.5 per inch at standard ASTM C519 conditions at the 75F mean temperature required for labeling. Run it by whomever is enforcing code in your area, and ask if it's OK to assume it's R5.5/inch (or even R5.0/inch) in lieu of a label.

    You could have a professional lab test a sample, I suppose.

  2. GBA Editor
    Martin Holladay | | #2

    This is similar to using lumber from a local sawmill. Some inspectors don't like the fact that there is no grade stamp on the lumber.

    I would approach the local inspector and describe the situation. Some inspectors are surprisingly reasonable. He or she may accept the insulation as long as you don't claim an outrageously high R-value per inch.

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