Hi there,

I am renovating an old 1850s farmhouse. The basement is in fairly good condition. It has a concrete floor and parged cinderblock walls that sits in front of the old stone foundation (which we believe is not in good condition). We got out house insulated last year with spray foam and had the rim joist of the home done as well. So the entire perimeter of the home has a good layer of the spray foam on it. The footprint of the house sits beyond the perimeter of the parged cinderblock basement walls. I’ve included photos as this may be confusing.

We wanted to make sure we insulate properly. Our initial idea is that we strap the parged wall and affix 3inch EPS foam (we have someone who is willing to sell us this used and at a discounted rate so that’s why we are hoping to go with this material) overtop of the strapping. We felt pretty good about this plan until we thought about the gaps in the cinderblock wall. Do we think that cold air would travel through the cinderblocks and up through the gaps? Any ideas here would be appreciated on best practices and materials. 

Note on pics – the big blue blanket is covering a door that leads to a stairway to the exterior of the home so we get a lot of draft through there.