Insulate above garage

Old 12-05-19, 06:05 AM
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Insulate above garage

I want to add insulation above my garage area, It is 10' high, 700 f2, fink style truss and supports of 2x4 24"oc. I live in Maine. I added a gable vent on one end of the garage, and it is attached to the house on the other end, There is a lightweight storage area over the joists with plywood laid on top. The area will not be heated, just insulated to try to keep it above freezing most of the year

I was thinking of laying in R-19 23" rock wool batts using wire batt supports between the rafters. I may install a ceiling next year.

Thoughts, comments, more insulation?
Old 12-05-19, 06:35 AM
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Since you have no insulation now R-19 would be a massive improvement. My garages are all insulated, walls and ceilings. Down here in NC in our coldest winter snaps (10 days below freezing, nights +5 to -5f) and they get down into the upper 30's. If we had more severe winters freezing would be an issue. It was better when I kept my diesel truck at home. It's big cast iron engine brought in a lot of slow releasing heat but with two cars in there there just isn't enough heat added to offset losses, mainly through the garage door.

I think R-19 is a good compromise between good R value and cost. I don't think you'll be able to ever insulate well enough to prevent freezing but you could get an extra month+ where it doesn't freeze. It's hard to get around the fact that you open a huge hole in the wall every time you open the garage door and let most of your heat out.
Old 12-05-19, 08:34 AM
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If your going to drywall Id just do the insulation afterward with blown in cellulose and save all the time an hassle of installing batts between the rafters!

Then for just a few dollars more in material cost you could get R40 (or whatever is recommended) with minimal extra effort!
maarkr voted this post useful.

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