Comments on: Possible Foam Insulation Problem? http://insulationmaterials.info/possible-foam-insulation-problem.html Benefits of Insulation - your home will be energy efficient with the highest R-Value. Products include Spray Foam, Rockwool and Cellulose Thu, 15 Sep 2011 05:21:15 +0000 hourly 1 http://wordpress.org/?v=3.1.3 By: Chris http://insulationmaterials.info/possible-foam-insulation-problem.html/comment-page-1#comment-1072 Chris Sun, 06 Jun 2010 14:56:19 +0000 http://insulationmaterials.info/possible-foam-insulation-problem.html#comment-1072 Good question. The simple answer is no. Adding foam to the underside of the roof will cause the shingle temperature to rise since you are adding more mass to store heat in the roof. The temperatures will still be no where close to causing delamination issues in the chip board or plywood. However, most shingle warranties will void after you reach the 190 degree point on the roof. Plus, the foam will not let moisture through, so if the roof ever develops a leak, it will degrade and rot the wood substrate before you realize the problem. I am not a big fan of installing the foam on the underside of the roof for the above reasons. It does work good, but has some potentially bad side effects. Good question. The simple answer is no.

Adding foam to the underside of the roof will cause the shingle temperature to rise since you are adding more mass to store heat in the roof. The temperatures will still be no where close to causing delamination issues in the chip board or plywood.

However, most shingle warranties will void after you reach the 190 degree point on the roof. Plus, the foam will not let moisture through, so if the roof ever develops a leak, it will degrade and rot the wood substrate before you realize the problem.

I am not a big fan of installing the foam on the underside of the roof for the above reasons. It does work good, but has some potentially bad side effects.

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