Extra Insulation = Garage Insulation
A combination of extra Roxul ComfortBoard IS and SmartBatt insulation gives the garage a comforting blanket.
I made up the insulation order back in the spring — long before the materials were needed. I had to make up material lists for many of the materials, so the sponsoring companies could make delivery arrangements and run the orders through internal channels. Working off the plans, my insulation take-offs were conservative. The short of it is that we ended up with some excess materials — in part because of the conservative list and in part because Bruce planned out the Roxul insulation cuts so there was no waste. So we put the excess to good use, insulating the garage walls and ceiling. Even though the garage isn’t heated, the insulation will buffer the deep cold of winter and sweltering heat of summer a little. Today, for instance, it was 14° F outside when I got to the site and the garage was a toasty 34° F. That makes a big difference when jumping into the car in the morning.
Bruce and I spend an afternoon insulating the garage ceiling. First we fit R21 SmartBatt fiberglass batt insulation between the joists. Then Bruce ripped the ComfortBoard to fit between the I joist webs precisely. When we lifted the rigid stone wool up between the joists, the bottom edge rested on the bottom flanges of the I-joists.
Tallied up, there’s about R-30 insulation in the floor system.