Recent content by rextang

Ok, I was following until the math on the polyiso on joist edges and 1/4” batt compression. I picked up the asphalt fiber board sheathing and foil faced polyiso at Menards, so that will go in tomorrow. R23 Rockwool is all special order everywhere in southeast Michigan.

thanks Dana for the thorough follow-up. If I were to leave the air gap open, tightly pack the cavity with Roxul and install the foil faced polyiso, will the cavity sufficiently allow moisture to do whatever it needs to do while blocking as much air movement (cold intrusion) as possible?

I have searched high and low and cannot seem to find a solid answer to my question. My ‘79 quad level has 2x10 cantilevers over a brick facade separating the lower level from the upper level. Having just removed the stucco style interior ceiling, I pulled out a mix of r11 paper faced batts and...