Air sealing basement beam pocket?
I have a concrete-wall basement from 1950. There are two beams in the basement that are triple 2x8 or 2x10. They rest in beam pockets in the foundation walls. There is a piece of sheet metal below them where they rest on the concrete, as a capillary break. I'm in the process of air sealing my sill plate and rim joist with expanding foam -- should I seal these beam pockets? If I don't, they will definitely leak some air, as a small length of the sill plate-to-foundation joint will remain unsealed. If I do, they supposedly may rot more readily over time, as it seems to be common practice to leave an air gap around the beam end to facilitate drying.
3 out of 4 of the beam ends are on foundation walls that are about 18" exposed above grade. The other one has more like 6" exposed above grade, so part of the beam is likely a little bit "underground". There is no waterproofing or dampproofing on the foundation exterior that I'm aware of. I'm planning to add a few inches of rigid foam on the interior foundation walls.
Should I air seal these beam pockets, or not?
Posted Jul 14, 2014 2:16 PM ET
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