Critters and waterproofing
I have an older garage with walls build with 2x4x8 that are spaces 24″ apart. The siding is just overlapped wood.
I am planning to reinsulate this space and I have already removed the old insulation (fiberglass and foam combo).
I now see the wood, it’s in fairly good shape with noticeable small gaps in the overlaps. I want to close up these gaps somehow, what is the recommended best solution for this.
My primary concern is critters as I am using the garage for food storage and want to make sure everything is sealed up good.
Also, the insulation I want to use is Roxul instead of Fiberglass.
Any recommendations with what I am doing here would be greatly appreciated, thanks a million 😉
James
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Replies
James,
It sounds like your existing garage walls have no sheathing and no water-resistive barrier (WRB).
The best way to proceed would be to remove the existing siding so that you can install plywood or OSB, followed by a WRB (perhaps asphalt felt), and then siding (either the same siding that is on there now, if it can be salvaged, or new siding). Even better would be to install the siding over a rainscreen.
If all of that work seems to be burdensome and expensive, you can try to figure out a way to cobble something together with the existing siding. One way would be to insert pieces of rigid foam in each stud bay, installed tight to the siding. These pieces of foam could be sealed into place with caulk, canned spray foam, or high quality tape at the perimeter of each piece of foam.
Once these pieces of foam were installed, you could proceed with Roxul.
By the way, it's hard to keep rodents out of a building. Paying close attention to airtightness at every stage of construction is a good first step.
Hi, I won't be able to finance the siding part of the project :(
I'll need to look at rigid foam. However, with the rigid foam in place wouldnt it cause compression on the roxul?
thx!
Any reason why I should not use this to seal all the spaces instead of foam?
http://www.homedepot.ca/product/pl-acousti-seal-vapour-barrier-sound-reduction-adhesive-825ml/972916
James,
If you install 1-inch foam board between your studs, then you'll need to compress the Roxul or fiberglass batts that you install to fill the stud bays. Roxul makes many different insulation products; some are more compressible than others.
You can't use caulk to seal the back side of your siding permanently. Wood siding moves constantly, due to changes in humidity and temperature, so any caulked cracks will soon open up.
All siding allows some wind-driven rain to get through to the back side of the siding. That's the reason that the building code requires the use of a WRB (and usually, sheathing).
The use of 1-inch-thick foam board is a cobbled attempt to make your wall work. It's not perfect, but it's less expensive than doing it right.
Hey Martin, thanks for the time and response.
I didn't want to use foam because I find that mice like to make a mess with it and it seems to be a comfortable material for them to nest in.
The acoustiseal stuff never dries, not sure how it would crack.. although, over time I can see this shifting. At least the Roxul repels water, not like a lot will get in there.
The other idea I had was to use tar paper against the siding.. anything else like that you can suggest?