House overhang insulation
bosshog2212
| Posted in General Questions on
My main floor overhands 4 foot from the basement. This section is extremely cold on the feet compared to what’s over the basement. What would be best way to insulate an overhand? I opened it up and currently it has batts in there. So thin piece of wood, then batt insulation then floor…. But there is a gap, nothing sealed.
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Replies
I'm a little confused by what you mean when you say there is a cap. what is the flooring material? My guess is that the best solution for you will be a layer of exterior continuous Rockwool Comfortboard insulation on the bottom side of the overhang as we all as careful attention to air sealing while you are at it.
Meant to say there is a gap.
Usually cold floors are caused by cold air leaking in. You want to air seal the underside of that overhang as thoroughly as you can.
Air seal with some spray foam ok at the seams?
boshog2212,
I would suggest two things.
- Block off the overhang over the foundation wall with pieces of foam board sealed with canned foam between the floor joists. This will stop air moving into the basement.
- Put a layer of foam board under the overhang and cover with plywood (or other protective cladding) to reduce thermal bridging.
Gaps around pipes, wiring, soffit vents, and other penetrations are major culprits. Use high-quality caulk, spray foam, or weatherstripping to seal them completely.
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