filling gaps between Foundation and Sill
I’m getting ready to finish a walkout basement and noticed that there are more than a few places where I can see through to the outside via small gaps between the top of the concrete foundation wall and the bottom of the sill plate. The gaps are pretty narrow, from less than 1/16″ to about 1/8″. What is the best method/product for sealing up this gap?
Thanks,
mledbury
Replies
Didn't use a sill seal strip?? Probably the best/simplest/cheapest solution is to jam foam backer rod (round foam strips used for caulk backing) into the crack from the outside, but that won't work for the smaller gaps. Best not to fill the whole thickness (from outside to inside) with something like spray foam as that will tend to trap moisture, but small gaps can be caulked (from the outside) or sealed with a small amount of foam.
Thanks for the advice Dan!!
same question came up today
our foundation ( subbed out) has a few low spots that are no more then 1/8 thick but about 2 feet long
we were thinking of miking up a little mortar mix , wet, and slopping that in under the foam sill seal. then bolting down the plate. I figured that way if a stud is right above it I wont get any flex in the sill
wouldnt that work good too??? or is that overkill ??
The sub said to just caulk it.