We are remodeling our bathroom and are in the process of framing/insulating.
We need to insulate 2 concrete block walls but don't want to eat the already small space we have. Which solution could work?
Currently, the wall has 1x3 furring strips and we were thinking about using them to hold 2 inches insulation board—leaving some air pockets—then installing the thinner 1/4 inch Hardiebacker board and then Redgard the hell out of it for waterproofing.
My concern is the furring strips won't hold the backer board and the ceramic. Other option we thought of was using the Schluter Kerdi board and forget about insulation altogether, so Kerdi board attached to 1x3 furring and then titling.
Is there any other option that you can think of? Will any of the above ideas make sense? Thanks for asking. We are in DC (U.S.) area so summers are really hot but winters are mild.