Polyisocyanate Foam Insulation

Polyisocyanate Foam installed on all exposed framing. Rafters, sheathing between floors, inside interior walls, etc.

Installation is designed to serve as an insulator as well as sound proofing.

Anyone ever encountered this type of installation?

Any noted history of problems encountered?

I recently inspected a home with Icynene insulation which I think is the same thing. I found little to be critical of regarding the insulation. Granted, I don’t know a lot about this insulation method but what I’ve read so far is very positive. Here’s a link to their website http://www.icynene.com/Products.aspx and I’ve also included a couple of photos I took and a link to a printout I included in my inspection report at http://www.icynene.com/assets/documents/PDFs/ConsumerBrochure.pdf .


Thanks for the info.


Here’s an installation video from Tigerfoam

It is an excellent product. My open foundation is insulated with it. If exposed to sunlight (UV) it will begin to discolour and break down. It should also be covered with drywall as it is combustible and gives off very toxic gases (Cyanide?)

Personally I would not use it to insulate the rafters. If you have a leak in the shingles you would be hard pressed to find it with foam in place.

Icynene is an open celled foam as opposed to polyurathane which is closed cell. This means that Icynene will allow moisture to very slowly migrate through it.

Icynene also remains somewhat spongy.

Would you please post a reference stating that this foam insulation must be covered with drywall?

Dave, this is from the Icynene website

15 Minute Thermal Barrier Coating List](http://www.icynene.com/ThermalBarrierCoatings.aspx)
Icynene falls under the plastic foam insulation section of the building code. The building code requires that plastic foam insulation be seperated from the interior by 1/2’ drywall or equivalent material (15-minute thermal barrier). A list of some coatings that have passed the thermal barrier test requirements over foam insulation is provided here as a reference.

Perhaps for the product that was used on your home this might be true but according to the Icynene website and brochures that’s not true.

I think you will find that if the attic area is to become liveable space the foam would have to be covered. If it remains an attic the drywall would not be required. That is what I have been told.

What about crawlspaces?

I believe foam insulation needs to be covered only in living/habitable space. :wink:

You see Poly-Iso all the time under EIFS (usually on the outside of the wall cavity, but have seen it on open frame sometimes I/S but always covered up in living areas with drywall, poly, etc. Seen once or thrice in attic area - had vapor barrier over on those installations.

I found this info on the ICC Evaluation Services Inc website:


Permitted to be installed uncovered in attic and crawl spaces…blah, blah, blah… but not on vertical surfaces…interesting.