Wine Cellar Project - Questions

I am constructing a basic wine cellar and have some questions about the construction.

Currently the walls are already constructed. The plan is:

  • Rip off one side of the dry wall
  • Expand frame from 2 x 4 to 2 x 6
  • Cover inside of wall with Tyvek (is Tyvek a good vapor barrier for a cellar?)
  • Attach rigid foam board between the studs
  • Use spray foam to insulate the edges or any open spaces
  • Green board on outside, finish and paint with water resistant paint

My question here is:

  1. What is the best way to seal the vapor barrier - i.e… where two sheets meet?
  2. Do the staple/nail holes attaching the vapor barrier need to be sealed? If so with what?
  3. From my understanding, there isn’t any insulation directly on the studs. Meaning you would have drywall/stud/vapor barrier/green board. Is this correct?

Lastly, any recommendations for cooling unit? I have looked mostly at Cellarpro. Any recommendations for wood racking? (I live in PA, close to Philly).

Thanks in advance!

  1. Tyvek is not a vapor barrier. Use a real vapor barrier material, such as 6 mil polyethylene. If you’re worried about small gaps, overlap and use duct tape.
  2. Vapor barrier goes on the outside (warm side) of cellar wall. The point is argued, given cellar will be more humid than rest of house, but the basic rationale is you’re worried about condensation, which happens only from warm to cold.
  3. You don’t need insulation on studs, although if you wanted you could bolt the rigid foam board outside the studs and then fasten the drywall through the rigid foam board. In fact, this might be easier than rebuilding the wall to be 2x6. Here’s thread on subject: Drywall over 1-1.5" rigid foam? | DIY Home Improvement Forum It would also make putting in the vapor barrier easy - staple it over the foam board.
  4. Not sure you need greenboard on outside of cellar. Should be dry there, unless you have moisture in cellar to begin with. That said, the added cost is small, and probably easier to do all greenboard.

What’s the flooring? Are you above or below grade?

No tyvek.

Thanks for the replies. Andrew: Sorry, my meaning was that the green board would be on the inside of the cellar. But since the wall is already there, I would only take off the inner drywall, and the vapor barrier would then go in first…but would wrap the studs. Ultimately the vapor barrier ends up on the warm side of the insulation, but not on the warm side of the studs if that makes sense?

I’m about 5 ft below grade.

Flooring is current poured concrete with ragged tiles. I’m tearing up the tiles and installing vinyl. Still undecided if I need a vapor barrier on the floor as I’ve seen arguments both ways?

Does this work as vapor barrier?

Spray foam the entire thing with closed cell and eliminate the need for a standalone vapor barrier all together. Also, I don’t think stapling the VB over the insulation (on the inside of the room) is ok to do - believe it always needs to be on the warm side of the insulation.

I know when I saw mine done with spray foam I was very convinced I had both a proper seal and vapor barrier. No way to screw it up. Piece of mind for sure.

Maybe I’m not explaining it correctly, as from my understanding my plan does have the vapor barrier on the outside of the room. From warm to cold, layers would be:

  • Regular dry wall
  • Vapor barrior and studs
  • Insulation
  • Green board

I read it wrong - you explained it correctly!

Although I think the question remains how to get the vapor barrier on the “outside” of the studs - OP appears to propose to wrap it around the studs so that each stud would be on the “warm” side of the vapor barrier even though it would be exposed to cold.

One option is to do that, and figure it won’t really be an issue. Another would be just to put sheets of poly in between each study (i.e., 14.5" wide) and then seal the edges with cans of spray foam, and figure the moisture transmission through wood will be minimal. Finally, if OP puts 1.5" of rigid foam on the inside walls over the studs, then the temperature where the wood is exposed in the cavity will be several degrees warmer than the cellar temp and even less likely to have condensation from moisture on it.

You got it Andrew, that explains it perfectly. I’m going to consider putting foam over the studs, I think even a thin layer should do the trick. Realistically 2 walls and the ceiling will be totally new, so I can put the vapor barrier on the outside/warm side of the studs…which leaves 2 walls.

Any recs for the racking and cooling unit?

Thanks again.

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Wine Racks America is what I used - very customizable and reasonable pricing IME. I made a lengthy post about it a couple years ago.

Cooling I’m using the “Galli” method - air conditioner plus a “tricker” to make it run cooler.

If you use closed cell foam, you may not need the expansion to 2 by 6 studs, unless you have some structural reason. Spray foam doesn’t end up quite filling the stud bay, unless you use a ton of it.