Hi, I am in the process of insulating by detached garage. I have installed a Hot Dawg unit heater and insulated the walls with R13 faced fiberglass. The garage has two floors. The upstairs is unfinished and has dreams of becoming a game room or studio apartment. When this happens I will install a seperate heating system, but for now it will be unheated. My question is what type of insulation should I install in the 2X8, 16" on center, ceiling of the garage? Since the floor above will be heated someday, I am assuming unfaced. Should I go with standard R-19 (6 1/4" thick), R-21(5 1/2" thick) or even something like MIRAFLEX R-25(8 3/4" thick)? I live in upstate NY, I believe the design temp is around 10 below. Thanks, Jeff
Insulating Question
Jan 16, 2005
3 Replies
Vapor barrier towards the heated side, that is away from the garage. Not in very warm climates that may be reversed.
You need to build to local building code as if the room is heated and garage is not.
Insulate according to your assumptions. Based on your assumptions the space above becomes a heated living space and the bottom is unheated much of the time. I would treat the ceiling the same as the floor above a craw space. Fully insulate the ceiling with R-25 insulation with the facing against the floor. You'll probably get all sort of advice, with facing, without facing, with it down, with it up. In the long run, if you are heating the bottom and heating the top even though it is only periodically, you can probably get by without facing.
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