Rigid foam insulation in an old brick home
Hi there I am hoping someone can help me with an insulation situation i am facing in my 1895 brick house. There is and has never been any insulation in the house and i just removed all of the plaster walls. I dont want to frame the walls with 2×4 framing to allow for the needed space to do spray foam insulation and I have actually heard that spray foam can be really bad for old brick walls. Plus this would force me to lose interior square footage in an already small house and ruin all my windows and door frames and be very expensive. The plaster and lathe i removed was all attached to 1 inch vertical furring strips which are all still intact on the brick walls spaced 16 inches apart. I was thinking the best solution would be to attach 1 inch Rmax polyiso boards with the foil facing to the furring strips, leaving the 1 inch gap between the poyiso boards and the brick and then drywalling over the polyiso boards. I would tape all the seams and do my best to seal the edges at the floors and ceilings as well. This would not give me the R21 code requirement i need for upstate NY but my building inspector tells me i dont need to be to code for insulation since my house is so old and has never had insulation and since achieving R21 using spray foam could damage the brick wall. Can anyone help me decide if my plan to use the 1 inch foil facing polyiso panels is a good idea? Would using the Rmax Durasheath panels be better than the foil faced panels? I would also insulate the attic to R38 with Batt insulation. Thank you! Any thoughts and info would be greatly appreciated!
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