Insulating Rim Joists on Existing House
Sorry about this long question
Folks – 100 year old house here in the north east (HVAC climate zone 4). I am trying to insulate rim joists for the primary reason that currently it’s like a vacuum pulling in unfiltered air causing bad pollen allergies in april/may. That’s my primary reason with the secondary being we are trying to finish the basement and will like to keep humidity out but we don’t need to go crazy building a tight envelope given other areas of the home like older windows, uninsulated stucco walls are unlikely to see upgrades (cost-prohibitive)
We have had humidity issues in the basement and some water leaks and also doing a waterproofing project from outside where they are going to excavate to the foundation, fill with gravel, etc. Currently, most contractors are suggesting open-cell but my research seems to indicate closed cell is better if basement has had humidity issues. Is this accurate?
We have access to only about 10% of the rim joists in the basement so as demonstrated in the pictures, we are going to demolish out the wood. We have already demolished all the side walls to investigate where the water leaks are and will be taking out the ceiling too to provide a sound insulated layer unless we can just sound insulate with the current ceiling in place
Also, my beams are anywhere between 3-5.5″ from wall. To keep costs low, can I simply use 2″ or 3″ of closed-cell or do I have to fill up all the way to the beams? Making the point again that I don’t need a crazy amount of R factor to keep the cold/warmth out but I do need some. My primary use case is to stop dirty unfiltered air coming in from rim joists which causes me ‘very severe’ pollen allergies. Also, we will only insulate rim joists now and will do entire wall after water leaks have completely stopped and we’ve proven out the exterior waterproofing work. After that, it’ll be new purple drywall. I will also be doing blown-in throughout the attic this summer.
Lastly, do I need to run any wires before doing rim joists insulation? I don’t think so given most wires should simply run behind drywall right?
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