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Community and Q&A

Caulk for glass block to sill

ranson | Posted in Energy Efficiency and Durability on

What caulk would be good for air sealing a 1/4″ gap between glass block (and plastic glass block vents) and the wooden sill plate over it?

As a general plan, is there anything wrong with caulking the exterior, waiting for it to cure, and then filling the rest of the space with canned foam from the inside?



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  1. user-2310254 | | #1


    I wonder about the aesthetics. Will you be able to see the foam through the block? If so, I would probably use a clear polyurethane to cover the gap and leave it at that.

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