Thanks for the quick response. I took your advise and stripped down the existing furring and put up 2 layers of 1" XPS. I used Tyvek tape to seal the seams and Great Stuff foam for the surrounding gaps. The 2 layers worked better than 1. I was able to slip the 1st under the metal electrical conduit and electrical boxes and the 2nd layer was cut around it. Great Stuff filled the cuts around the conduit. I will put 1x3 furring on top of it. The 3/4" gap created between the xps and drywall is just enough space for the conduit.
I am planning on placing the furring 24"OC. ( 4 screws to cmu per 8' strip) Since I am using 5/8" drywall I read that this is no problem. Agree?
Also, 3/16" tapcon or 1/4" tapcon for attaching the furring?
The tapcon instructions/website state that a hammer drill must be used on the cmu in conflict with your recommendation above. I tried a regular drill in the past and it has
By the way. Know an easy way to cut a channel in XPS?