My garage

[cardz_300]

I'm almost done with my car garage, and I've just put up some metal stud framing, leaving a couple of inches of space from the poured concrete foundation. I made that gap so I could run a bunch of utility lines. I've already sealed the foundation with waterproof paint, and I'm planning to insulate that new wall with Rockwool.

But I'm a bit worried about the air gap between the insulated wall and the foundation. Thoughts?

 

[WrapAndTrap]

I'm sure the air gap is good, but make sure there's enough air flow to keep moisture away. You might want to put up a vapor barrier on the warm side of the insulation so moisture doesn't become a problem.

 

[Millirack]

To hide wires and pipes, attach furring strips to the foundation. Run the stuff you need between them, add foam, and then put up your metal studs with Rockwool.

 

[Passionfru1t]

I'm sure the air gap is good, but make sure there's enough air flow to keep moisture away. You might want to put up a vapor barrier on the warm side of the insulation so moisture doesn't become a problem.

I agree, OP needs to put it on the warm side of the insulation, which in this case would be on the inside of the garage, on the face of the metal studs.
This prevents warm, moist air from the garage from hitting the cold concrete foundation and condensing, which is a big cause of mold and moisture issues.
Make sure the vapor barrier is a continuous sheet with all seams taped

 

[glass3s9uy]

I'm almost done with my car garage, and I've just put up some metal stud framing, leaving a couple of inches of space from the poured concrete foundation. I made that gap so I could run a bunch of utility lines. I've already sealed the foundation with waterproof paint, and I'm planning to insulate that new wall with Rockwool.

But I'm a bit worried about the air gap between the insulated wall and the foundation. Thoughts?

you know that the air gap is a double edged sword: You've created the gap for utilities, but that space can also be a perfect channel for moisture. The concrete foundation will naturally breathe and transfer some moisture from the ground into that air gap. While your waterproof paint helps, it's not a foolproof solution against all moisture.

 

[theb00m]

I recommend bringing the insulation closer to the wall or using a rigid board directly against the concrete to cut off air movement. Just ensure that you have properly sealed the top and bottom to avoid the air circulating freely. Otherwise, this can cause problems in the future.

 

[Tir_McDohl]

I’d be sketchy on leaving much of a gap unless you can ventilate it or seal it well. If the gap is sealed and controlled, okay... but if air moves in there, it’ll kill your thermal and moisture control.