I’ve got an attached unfinished garage and laundry room. I’d like to put something on the walls to attach shelves to sort out my mess of stuff and to convert the space into a more usable workshop.

This is an older house (1950) and has a sort of weird construction. Some of the exterior walls are brick over a tar paper over studs (exposed on the inside) - no sheathing as far as I can tell. Other walls are partial brick (3 feet up) with the top consisting of siding over tar paper over 3/4” tongue and groove sheathing.

Interior walls in the garage are tongue and groove sheathing on the unconditioned side, studs, and then drywall on the conditioned (living space) side.

The garage has unfinished ceilings and I can see light through the ridge and soffit vents - so it’s unlikely that I will be able to make this into a conditioned space.

So - what are my options?

I’m in central Texas (zone 2A?) - hot/humid.

For the garage space I’m thinking of painted plywood over studs (no insulation). enter image description here

For the laundry room - moisture resistant drywall and then some sort of tile board. Also no insulation.

enter image description here

Do I need any sort of vapor barrier anywhere? I’m worried about growing mold - I’d like to avoid that.

  • Vapor barrier newer harms
    – Traveler
    Oct 4, 2023 at 4:49
  • @asinine, that's certainly not true, and answers go down there.
    – isherwood
    Oct 4, 2023 at 12:51
  • Why would you not insulate? It's fairly inexpensive and would certainly keep your space cooler during the day.
    – isherwood
    Oct 4, 2023 at 12:52
  • 1
    Isherwood - I’m not sure if I should insulate. This is an unconditioned space so I’m not sure it makes sense to? Also, if insulating - I’m not sure if I should use faced or unfaced insulation due to the climate zone. Hot/humid climate guidelines are to have the vapor barrier on the exterior and not the interior.
    – Gary P
    Oct 4, 2023 at 18:22

1 Answer 1


If you are NOT going to condition the space, the vapor barrier will simply be a waste of time, money and effort.

You're going to have the same temperature and humidity inside and outside, so you're not going to have any vapor attempting to move from one side to the other, nor condensation on the cold side because there won't be a cold side.

  • You sort of imply that moisture results from temperature differentials. In fact, it mostly comes from human activity, including respiration and perspiration. It's likely that interior humidity will be higher.
    – isherwood
    Oct 4, 2023 at 12:53
  • Will that interior humidity be significantly high enough in the hot, humid Texas summer to cause condensation? Especially since the roof is vented?
    – FreeMan
    Oct 4, 2023 at 12:58
  • If the RH was already near 100%, why not?
    – isherwood
    Oct 4, 2023 at 12:59
  • If you're not going to insulate it, then who cares. I couldn't tell you the last time I hung a sheet of plastic on a wall. Either outside is Tyvek, or it's brick and use faced batts if only because they're easier. There's already some tar paper in places... zero insulation and two vapor barriers is called the sandwich.
    – Mazura
    Oct 5, 2023 at 1:05
  • Right - that's what confuses me. If I put in insulation that's kraft faced, then doesn't it form two barriers? And then since one of the rooms is a laundry room, if I use the moisture/mold resistant drywall doesn't that also form a cavity for moisture to get trapped?
    – Gary P
    Oct 5, 2023 at 1:48

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