We take possession of a new-to-us house on August 1st and I’ve got a couple of weeks to do some work on the house before we close on our current house. Painting and some flooring are our first concerns, but if we finish that up in time then I’d like to get started on the garage.
There is living space over the back half of the garage, and attic above the other half. The garage (20x18x9) has FG insulation inbetween most of the joists on the ceiling where the living space is and none where the attic is. On the walls, there is insulation where the walls meet the house and some on the exterior walls and some not. The attic above the garage is insulated.
In the interior, I’d like to drywall the ceiling and put up some sort of tongue and groove siding on the walls. I’m wondering what to do for the insulation and vapor barrier? I’ll add insulation to all the exterior walls, but should I also add it to where the attic part is (I’m guessing not since there is already insulation on the other side of the plywood)? Do I staple a poly vapor barrier to the studs outside the insulation (adjacent to drywall/paneling)? Does it matter if there is housewrap in between the siding and the plywood (I’d have to cut a hole to find out)?
Here’s a couple of pictures of the garage. I’m in south western Ontario right across the border from Detroit, MI. Cold winters and humid summers. The garage will not be heated.
thanks – mark
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Here's the little guy who has promised to help :
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Check your codes. Since you have living space above the garage, you made need fire rated walls & ceiling -- as in 5/8" drywall properly taped and seamed. You could put plybead over that on the walls. (Or real beadboard, if you have a couple of thou' extra laying around. <g>)
Since you are not planning on conditioning this space, vapor barrier is not absolutely essential. But it's so cheap, why not go ahead and put it in just in case plans change in the future? If the attic is not conditioned and is thermally isolated from the house, don't worry about insulating that. If you do, you need to make sure you don't mess up the venting for your roof structure.
And make sure your helper doesn't outwork ya and run you ragged!
Mike Hennessy
Pittsburgh, PA
Don't know if I would put a vp below a condidtioned space. Most of the time it goes on the warm side of an assembly. It could create condensation from any moisture migrating down from the room. Most likely why they are using unfaced batts already.
Now if he heats the garage, I agree.
He should heat it. His helper will like it after he boots the od man out to work on his own wheels in a few years :)
Dave
Doh! Badly-worded post by me. Vapor barrier on the exterior walls only, but I'd still put it in now, rather than chance having to tear off the finish to do it later.
(Hey, his helper probly woulda caught this error.)
Mike HennessyPittsburgh, PA
Thanks - I'll add to VB to the exterior walls. The cost isn't the issue, but I don't want to create any problems by adding the VB. I'll add it to the exterior wall part only.I won't be heating this attached garage, but there is a detached 2-car garage out back of the house that I am going to insulate and heat (will add VB). That will become my new woodshop.Though I bought my little helper some 'plastic' tools he prefers to play with my real tools. The hammer is his favorite and I've got to make sure I don't leave it laying around for fear of getting some extra holes in my walls!cheers - mark
"The hammer is his favorite and I've got to make sure I don't leave it laying around for fear of getting some extra holes in my walls!"
Or worse, your feet!
Mike HennessyPittsburgh, PA
I have a picture of my grandson (adopted son at about that age) using my 18v Dewalt drill, that was used in an article in People Magaizine. He is ten now and still considers that drill his. Take a guess at the number of holes I had to repair untill he learned what was off limits. Course by then he had graduated to shooting screws <g>. DW said all those thing had to stay in the shop. She didin't see as much humor in finding 20-30 piffen screws in the walls as I did <G>.
Dave
Who put that insulation in?
I'm not even playing an expert on tv here, but, I'm pretty sure Ontario has soem very specific codes on living spaces adjacent to garages, as well as where and how and what type VB goes in, along with some strict rules on insulating too.
So, you probably have to go ask who ever the local municipal authority is about what would be required.
Unless you are keen to have Mike Holmes show up and rip it all down <g>.
I'll bet that you have to completely enclose the garage space in drywall with fully taped joints. You could then put beaded/lapped siding over the walls or ceiling.
But, I'm guessing. From the middle of Texas.
Welcome to BT, though.
The insulation was probably installed about two homeowners ago during a major renovation. Sometime in the early 90s. My local library has a code book and I'm going go check it out this week before I proceed. There's plenty of other stuff in the house that is below par. IE the bathroom vents into the attic!cheers - mark
"IE the bathroom vents into the attic!"
DANGER Will Robinson! ;-)
Mike HennessyPittsburgh, PA
If the garage will remain a garage (not a teen's apartment, eg), is not heated by the house furnace, and will not be continuously heated by an unvented space heater (which clearly would not be a good idea anyway), then there is no need for a vapor barrier on the outside walls or between garage and attic. (However, local code may require a vapor barrier anyway.)
The reason no VB is needed is that there is no significant source of moisture (human bodies or combustion gasses).
Between a garage and an inhabited area above there should be the following, top to bottom:
-- Finished floor
-- Subfloor
-- Vapor barrier (if possible)
-- Insulation
-- At least one and maybe two layers of fire-rated drywall.
Fiberglass insulation should not be left exposed on either the "inside" or "outside" sides, since being exposed allows air to circulate through the fiberglass, demolishing its insulating value. (And besides, fiberglass is a mildly nasty stuff to get on you, and so should be enclosed to keep it out of the air.)
It doesn't greatly matter whether there's housewrap between siding and sheathing, in terms of what you can do now. Housewrap is good to have because it greatly reduces air infiltration (and in doing so it can improve the effectiveness of fiberglass insulation somewhat), but it isn't a vapor barrier and does not in any way conflict with having a vapor barrier.
[quote]
Between a garage and an inhabited area above there should be the following, top to bottom:-- Finished floor
-- Subfloor
-- Vapor barrier (if possible)
-- Insulation
-- At least one and maybe two layers of fire-rated drywall.
Thanks for the information Dan. I'll see about adding a VB before finishing off the garage with drywall. cheers - mark