You want the vapor barrier on the outside of the walls to the cellar, not the inside.
As for that space, you could redo the studs, and have space for some racks under the stairs. But personally I wouldn’t bother - it will be hard to reach and not worth the effort to get another ~200 bottles of storage. But, if you really want it, I would find some way to have a rolling cart to slide stuff in there - i.e., put racking on wheels so you can roll it in and out as needed.
Sorry, I meant walls that are exposed to the outside vs the interior walls. This is the vapor barrier on the outside two.
I would probably add a vapor barrier to the inside walls if you are going to leave a space. Is is an excellent place for condensation and ultimately mold to start growing.
I would redo the vapor barrier unless you are dead positive it has a good seal. The cost of doing it right now is nothing compared to the cost, pain and suffering of finding out after you’ve finished your project.
We’re seeing some potential issues with getting a vapor barrier on the ceiling, what are our other options? Is spray foam probably our best bet?
It is more expensive, but when it is in and you have a perfect seal you’ll be happy you did.
Yes to spray foam. Hire a contractor to spray it in. Do the walls as well if possible. Expensive but worth it!
Going for spray foam on the wall around the door and ceiling. Any idea what to expect for cost? As for the space near the stairs, we’re going to drop a new wall (2x6 studs) down in front of it and use vapor barrier plus insulation. Existing vapor barrier and insulation on the two exterior walls look good to us so they’re going to stay. New dimensions of the room after the wall is added will end up being about 8x10.
Are you going to DIY it? It will be a tank.
If you hire a contractor, depends, but my guess is it won’t cost much more to do the whole thing in spray foam once the contractor is there to do the ceiling.
Going from memory, I believe Gold’s book suggests a less than perfect vapour barrier in the ceiling is desired vs. perfect when going passive (or mostly passive). Worth googling if you can avoid bringing in spray contractor. DIY Kits are fairly affordable last I saw.
Bought a small spray foam kit to see if diy is feasible. I think I remember seeing 3" for ceilings and 2" of foam thickness for the walls, can anyone confirm?
If you are using closed cell foam its roughly 6.5 Rvalue per inch. The short answers is you should get as much as possible without overspraying. I’d try to get closer to 3" in the walls and 4 in the ceiling.
Anything wrong with foam plus regular insulation to fill the full cavity?
Nope. Just be sure to used closed cell foam so it acts as a vapor barrier.
Here’s the new wall being built and installed with the vapor barrier in place. Pretty happy with the result
Did a test panel with the foam spray. This stuff is COOL. Learned a bit by doing it, going to have a plan of attack for the spray pattern next time. The little canister just filled this space. Will be getting a full kit sometime this week.
What’s the pipe or little doodad coming out of the slab in the lower left corner of the picture? Some plumbing thing that you might want to have access to in the future?
Fortunately there’s access on the other side of the wall so we’re good to go on covering it
I just did a similar sized cellar with a room like yours, outside wall in basement with the window. Happy to share my construction plans and costs. Im not handy so I had a contractor do all the work so the room build out (minus racks) was about $9k. Racking and cooling unit cost me about another 9k. Granted I went a little higher end on the racking.
One suggestion, seriously consider doing closed cell spray foam insulation. It’s an extra cost but good piece of mind and amazing for filling all possible areas of exposure/gaps. Also make sure you have a real professional install it as it’s tricky to do. I let my regular contractor do it and if I could do all over again I would not go that way again. I had to really watch him to make sure he wasn’t screwing it up. for example he wasn’t spraying over the exposed heat/cooling ducting that was in the ceiling!!! that could have been really bad if I hadn’t caught it.
Short answer yes.
Longer answer - you should try to make sure you have a good amount of foam; otherwise you could get condensation between the foam and fiberglass, which of course would be a bad thing. Looks like you have 2x6 walls, so if you get a good coat of spray foam (2"+) and fill the rest with fiberglass, you’ll have some great insulation. (BTW, this is how I did it).