Frost wall wider than framed wall
jimmewkill
| Posted in General Questions on
We have a single floor house on top of an insulated concrete slab. As per the title the frost wall is inch or so wider than the built wall. As we’re in Northern Vermont the cold from the exposed part of the frost wall can be significant. I’ve seen the detail a few times where the same situation is designed, but can’t find any solutions.
One potential way to go is to cut the concrete out and fill with 2” insulation board. But happy to hear other avenues. Attached a drawing from GBA which is similar to our situation – the right hand detail is the one to look at.
Thanks in advance.
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Replies
jimmewkill,
Is this still at the design stage, or already built?
The foundation and wall are already in place.
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You can add insulation to the inside, outside or both. Can you make the wall studs deeper, toward the interior? If not full height, then just enough to cover the concrete? If not, I'd probably insulate the foundation exterior.
Perhaps a pic of the actual condition. It seems to me the heatloss would not be over significant, but perhaps condensation might be a thing. To large for trim to cover it?
Heat loss is one issue, but perhaps a bigger concern is the risk of mold growth when you have cold surfaces that are exposed to conditioned air. It's very common to find mold behind baseboards on slab-on-grade homes in cold climates.
The risk of condensation is one aspect, the interior skin is osb. While it is up off the concrete, the potential presence of moisture is something I’d be happy to avoid.
Added photo at front door.