Brick with balloon frame: insulation
First of all I want to apologize if I get terminology wrong, I’m an electrician by trade and just now getting into DIY construction. I have a 1940’s all brick balloon frame home. My question is if I would be helping or hurting myself if I applied closed cell spray foam in between the floor joists in my basement to keep air from rising from my basement through my walls. My house is like I said all brick, brick foundation also; and there’s no plate to rot away. Also there’s no insulation other than the 2 layers of brick itself, and I’ve been slowly remodeling and adding spray foam to the new stud walls I’ve been adding as I go along. Thank you and again sorry for my lack of knowledge.
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It doesn't take closed cell foam to block the air paths to the balloon framing. If there is plank sheathing between the studs and the brick veneer it can usually be retrofit-insulated with blown cellulose, which is very air retardent even at low or mid-density.
If the joists are embedded in the brick it's a different moisture problem for the joists than if they're on iron/steel joist hangers. Some pictures might be useful. Your location / climate zone also matters.
Brian,
As you may know, insulating the interior side of an old structural brick wall (a so-called "multi-wythe brick wall") can lead to brick deterioration resulting from freeze/thaw cycles. (For more information on this issue, see "Insulating Old Brick Buildings.")
But as long as you aren't using the closed-cell spray foam a insulation -- as long as you are simply using small amounts of spray foam for air sealing (preventing air from rising up the balloon framing cavities) -- then there is no reason you can't use spray foam that way.