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Community and Q&A

Is it safe to paint Polyisocyanurate Insulation?

bking2006 | Posted in Green Products and Materials on

I have a lot of Polyisocyanurate Insulation in my basement. We are not at a point where we can finish our basement, but I’d like to at least get it looking a little nicer so it can be used as a playroom – carpet on the floor, paint on the walls.

The top half of the walls is this Polyisocyanurate Insulation. It has a reflective aluminum facing.

Is it safe to paint this? Will it decrease the effectiveness of the insulation?

Thank you!

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  1. Expert Member
    Dana Dorsett | | #1

    Unless it's a fire-rated type, leaving polyiso uncovered in a conditioned space (even an unfinished but used space) without a thermal barrier equivalent to half-inch wallboard is a code violation and a fire hazard (though the hazard isn't huge in most situations.)

    The right thing to do is to put up a code-legal thermal barrier and paint the thermal barrier before using it as playroom. Depending on your climate and the R-value of the existing polyiso you may even want to put up a non-structural studwall insulated with unfaced batts as something to hold the thermal barrier. At a minimum 1x furring through-screwed to the foundation with TapCons 24" o.c. can be used as something to hang half-inch wallboard to serve as your paintable surface and thermal barrier.

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