Best foam/product to air seal large and irregular penetration
I’m trying to air seal around the intersection of my cathedral roof trusses and the sheathing that rises up to meet the roof deck. I’m left with some one inch to two inch openings where there are diagonals in the truss. It’s possible to tape them up but I had hoped to find a foam solution. Is there a foam product that can be a long term solution?
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If I were you, I would buy a two-component spray foam kit (not the little cans of one-component foam). This is a classic example of a good place to use spray foam
I would simply use the little cans of one-component foam. It's more reliable because you don't need to get the mixing right, and it's more environmentally friendly--doesn't have the high-global-warming impact blowing agent that the two-part foam has.