Outside Garage Wall Insulation Question

[OJ Bartley]

I'm in the process of cleaning up and finishing the garage to be a more useable space, and have one unfinished wall that the builder left open. The garage is attached on 2 walls (left side and behind from the perspective of the photos below) with the door wall obviously being an outside wall.

I had previously added some panels to the door which helped, but I want to close in the rest of the wall and am not sure how I should insulate before I do it. The areas in question are the sections above the door, and the tall skinny sections beside the door. You can sort of see in this first pic that the area was originally just exposed OSB on the inside, and brick outside. I have no idea if there's anything in between, but I doubt it.

When I did the door panels, I had some leftover so I tucked it in between the studs (just pressure fit, no adhesive), hoping it would help a little. I had planned to just add some standard pink fiberglass on top of this and drywall, but I thought I should probably check with someone who knows what they're doing because I don't want to start a mold farm.

My main question is: do I need to put up some kind of vapor barrier if I insulate this wall, and if so, what's the correct order to layer? Should I take the styrofoam down, fill with pink stuff, staple some plastic VB and then drywall? Can I leave the styrofoam and do that?

The adjoining walls are all drywall finished to the corners and I can't see what has been done there. They're taped and mudded tight to the unfinished wall. This space is unheated and is not cooled in summer. It's a relatively small section of wall, but I want to keep the garage temps a little more controlled, since the room above is affected quite a bit by it in both extreme heat and cold. Any input would be greatly appreciated.

Oh, I think Toronto is considered Zone 6?

 

[thedoc]

Garages that I've seen finished stick the pink stuff in there. U can get the pink stuff with vapor barrier or just put plastic over it after its stuffed in there. Drywalling that is a bit tuff and takes a lot of cutting and may have to work with small pieces. Mud joints after for finished look. Bat insulation will give u a better r value than that foil.

 

[northeimcustom]

looks like you need some insulation on the sides by the garage door frame as well........

 

[OJ Bartley]

Thanks doc and north. I'm unsure about the vapor barrier, because this isn't a heated/cooled space, but I have done some more reading and found a few things like this:

"If the home is relatively recent, then there is [ought to be] an existing vapor barrier between the interior space and the garage. It is [ought to be] facing the interior heated space. The same logic would apply to a heated garage at the exterior walls"

...which in my case would mean removing the styrofoam, putting up new pink stuff, and then a vapor barrier on top (on the garage side of the wall) before drywall. The trouble is that there are so many conflicting opinions online that it's tough to sort out what is right and wrong.