Adding exterior rigid insulation to Superior Walls
Martin – do you know if it is advisable to add extra exterior rigid foam to Superior Walls? I looked on their website and it only mentions adding insulation to the interior stud bays. But this doesn’t resolve the thermal bridging issue through the concrete studs. Would there be any moisture issues if I’m effectively creating a sort of poor man’s ICF? Any suggestions for attaching this? Superior walls high psi concrete is notoriously hard to penetrate evidently. Is it ok to just press them against the walls and have the backfill hold them in place? Thanks to anyone for any suggestions.
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1. I see no reason why you couldn't install rigid foam on the exterior side of Superior Walls. There are no moisture concerns -- the concrete doesn't mind moisture in any case.
2. Exterior rigid foam can be held in place by the backfill as you suggest, or it can be secured with foam-compatible adhesive or canned spray foam.
3. You need to come up with a plan for protecting the above-grade portion of the exterior foam. For more information on this issue, see How to Insulate a Basement Wall.