Thoughts on insulating a balloon-frame brick house
Hey guys I’m new here and have been reading just about every article there is but I’ve run into some gray area, where it seems it’s too open ended to actually have a straight forward answer.
So im planning on insulating a balloon frame brick house built in 68. Im in region 5a, pennsylvania. Heres what im working with: 3.5inch brick, .25in air gap, a couple mil fiberboard wrap(?), and then another layer of thin cardboard looking stuff, I think the name ends with a sote. Homasote? Then balloon framing, 2x4studs every 16inches on center. As is, there is no noticeable drafting in house. Winter heating is significantly cheaper than summer cooling in terms of energy consumption (3x energy difference comparing apples to apples). No known water infiltration.
my plan is to use a rigid foam in the wall and finish the fill with a slightly compressed fiberglass for additional r value. I was planning on using xps, or possibly eps, at no more than 1inch, but was thinking of going 3/4 if internal thickness of rigid doesn’t matter. Internally, would the thickness of the rigid mean I wouldn’t need kraft paper or a vapor retarder? Should I even bother with the rigid, and just go with batts or blow in fill, and caulk seams?
The thickness of the rigid is what I’m stuck on. I’m unsure If the rules change for internal rigid/batt insulation. If I need to go thicker foam I’m probably going to end up doing 2inch foam with cellulose or fiberglass blow in. Thoughts? I’m planning to stay with the original 2×4 cavity, I’m not planning on worrying about the thermal bridging issues from studs, but if someone’s willing to enlighten me I’ll bite.
Also if anyone has preference over another foam, iso, eps or xps I’d appreciate your thoughts for internal insulation and air stopping. (I am aware od the blowing agents and green values) For my wall space and climate I was thinking iso would be too thick to be the main insulator.
So any thoughts or modifications is greatly appreciated. If I forgot to mention something or neglected a forum rule let Me know I’ll try to oblige.
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