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Insulating and Heating Floor Above Garage

CdnHandiMan | Posted in General Questions on

Hi guys,

I really enjoy reading the site and seeing the Q and A stuff.
I had a local builder build a 2 story garage and I worked on job with him. I’m no expert but I’m handy enough to assist and be directed to build framing and other projects.
Here is the breakdown and some of my issues
Canadian cold climate in winters
Garage is 50 feet from a big lake
I have not decided if I will heat the garage but I want to live upstairs for months each winter.
concrete pad 24×32
2×6 walls 24×32 @ 9.9 feet high
2×10 floor joists 24×32
then we built 2nd story on top at a reduced size 22×32 to get gambrel roof
2×6 walls 2nd story @ 8 feet high
Truss engineered 4/12 pitch
OSB walls and roof
Plywood on 2nd story floor
Garage door is R18 insulated

Looks good and the builder is an old school guy who has been building for 30 yrs. Great guy and works hard with passion for what he does but he did not design and I worry there might be some little issues. We ran out of house wrap 2 days ago and it still needs to be finished in wrap this week.

Issue #1
How to insulate the area between garage and 2nd story because there is a foot off set on 2 sides and I can see into downward area of roof. Debated covering and some ppl say spray foam but we have carpenter ants a plenty in area and I hear nothing but horror stories about foam and carpenter ants.
Issue #2
I have heard many different opinions so I wanted to put this out there. Do I vapor barrier just the walls in garage and 2nd story apartment then ceiling under roof or vapor barrier garage ceiling and 2nd story ceiling?
Issue #3
Unsure of how to heat.
I have not decided on heating garage but would like to be able to heat garage if I want. I’m worried about if I don’t heat garage while I live above the floor will be freezing. Do I insulate floor and vapor barrier? I really have no clue what’s best. I do not want to do wood stove for insurance issues.
I’m running out of money so I would love to know what is best.
Options are to get propane or go electricity.

Sorry it is so long winded but I would appreciate some advice.
I’m looking at doing split heat pumps as secondary and a/c for summer.

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  1. GBA Editor
    Kiley Jacques | | #1

    That’s a nice-looking project. In this article, Martin Holladay answers some of your questions and provides illustrated construction details for How to Insulate a Cold Floor.

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