Sealing between floors on 1.5 story home?
High, I am currently building a 1.5 story home with 2.6 walls that will be insulated with blown cellulose. I am sealing all joints and penetrations with caulk and spray foam, and will doing R-38 in the vented attic.
I am concerned about the open space between joists between the upper and lower floors. I want to know if I should seal off this space so that the hot attic air does not infiltrate between the floors.
The upper floor is only about 1/3 the size of the lower floor and I only need to do supplimental sealing between joists in one directions since the joists running longintudinally block it in the other direction.
I have though about just filling this whole void with insulation, but that is not so simple either. The upper floor level is on top of a ten foot cieling. but some of the rooms under it have 9′ cielings. So there is too big of a hole just to fill and then I have a hot floor on the second floor. I could block it off though with relative ease. In retrospect I should have made all these cielings below it be 10′, but it is too late to fix that now.
Anyway, I wanted to know if there is a standard recommendation for the airspace between floors in a 1.5 story. Seal it or leave it open? If I seal it tight, are there venting concerns?
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