Garage insulation

[Countryrocker213]

I just had a 24x24 detached garage built and I’m looking to insulate and “finish” it. I’m confused with all of the information about vapor barrier or not. I plan on putting in an electric heater but probably won’t use it more than a couple times a week in the winter. Is kraft backed insulation acceptable for this? I’ve read an insulated unheated garage can create mold. If it makes a difference I plan on putting osb over the insulataion. Thanks

 

[The Cobbler]

there seems to be a real conundrum on vapour barriers in garages.
some say yes, others say no. my insulation guy says no. I did tho .

 

[rust in the eye]

A friend makes a very good point about(breaches in) vapor barriers: "Vapor barrier? two coats of latex paint, that's my vapor barrier."
FWIW my garage is insulated with kraft faced batts

 

[Notgrownup]

I have tyvek wrap so I didn’t use it, I used paper backed pink insulation, blown cellulose in the attic....18000 btu mini split 24x24 with 10’ ceilings.

 

[matt_i]

Imo to need a vapor barrier it needs to be concentrated and "driven" from somewhere like a shower or cooking area/kitchen.

Its one thing to use an air barrier to better capture heated air that wants to leak out thru every tiny crevice but my opinion of needing a vapor barrier for a garage is that you don't.

Your best bet is to keep air moving with a ceiling fan that's always on low and try to keep the big door closed as much as possible.

 

[u2slow]

Seems foolish to board up a shop and not put in a vb that may be required later, i.e. if converted to a living space. Not a costly extra step for a DIYer.

I was allowed to use tar paper under the siding, so I'm not worried about trapping moisture.

 

[Countryrocker213]

I have no issue doing the vapor barrier I just wanted to make sure it wouldn’t be a mold issue with it not being heated most of the time.

 

[u2slow]

I have no issue doing the vapor barrier I just wanted to make sure it wouldn’t be a mold issue with it not being heated most of the time.

Good question. I'm using roxul too. Supposed to not breed mold. One wall is done... only 3 more plus a ceiling to go. No heat yet.

 

[Hallucar]

Geez, I never even thought vapour barrier could be an issue. I insulated my detached garage, then put vapour barrier, then drywall, then paint. Didn't really think much of it. I have Tyvek with Hardie board installed for siding.