Rim Joist Area
Zone 6 Mpls
Fairly versed on what needs to be done to insulate this area. In my last 1940’s house the rim joist area was a cavity in which spray foam or foam board could be placed inside as it had 4-5 inches of depth. Having bought a new house around same age, I begun the beginning stages or remodeling the basement and this was on the list.
The ceiling was sheetrocked however we needed to remove some of it which also exposed the rim joist area. What I uncovered was 1×10 wood blocking between the joists. This blocking is flush with the face of the cinder block. foundation wall (in other words their is no depth to the rim joist cavity), 1st picture
Being a student of these forums I decided to see if I could remove this wood blocking and expose the rim joist cavity in preparation to spray it with foam or XPS squares foaming them in place. Instead after I popped the 1×10 off, the cavity instead of a hollow cavity it was filled with concrete. The depth of the cavity is literally .75” relative to the cinder block as the wood blocking is flush with cinder block foundation. 2nd picture (note as you can I didnt fully remove the wood blocking)
Can I just leave the wood blocking in place for the other cavities and attach my XPS foam board directly to it and spray foam the seams? Or do I should be removing the 1×10 wood blocking and attach the foam board directly to the face of the brick that sits between the joists . This blocking is toe nailed between the joists and just assume leave it place attach my foam to the face of the 1×10 blocking as it will be fair amount of work to remove this in all the cavities, unless their is a real value add to removing it as to attach the XPS to the brick instead.
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