[squarewav]

My bath is in an old apt complex converted to condos. The exterior wall was actually strips of metal covered with metal lath and plaster. The last contractor tried to go over the strips of metal with metal studs. At first I thought it was pretty solid. But after close inspection it's not that plumb and the screws are not grabbing the 25 gauge studs.

http://i.imgur.com/a47DYzP.jpg
http://i.imgur.com/3XLS5Id.jpg

So I want to rebuild this wall with 1-5/8" 20 gauge studs and track and put 5/8" concrete board directly on the metal with hot galv screws.

However, I have never done any kind of framing like this so I was hoping to get some tips about how to actually assemble this.

Note that I have to use 1-5/8" studs because the bypass shower doors have to fit, the toilet is already very close to that wall and the radiator cover cannot be moved.

Here is my framing layout:

http://i.imgur.com/BjiCTgZ.png
http://i.imgur.com/999E7FY.png

Does this look sane?

 

[squarewav]

So I have this framed up with 20 gauge:

http://i.imgur.com/28pg1mO.jpg
http://i.imgur.com/MnbHM6i.jpg

But as you can see, there is an exterior wall that is just cinderblock and it looks like the outside brick facade is exposed around the radiator. So this looks like a good case for insulation.

Can someone recommend a good way to insulate this wall?

Actually this place is so drafty, I think some kind of vapor barrier would be even better. Is there some kind of thin insulating vapor barrier that can just be placed behind the whole wall.

Note that the wall is actually not fixed in place yet. I designed it so that I could pull the entire assembly away from the wall. So I could get back there and attach something that is one big sheet if desired.

Ideas?

 

[Msradell]

Depending on what your budget is the best way to insulate them well may be to use spray foam insulation. It will actually provide very good insulation plus completely seal out drafts. In addition if you use closed cell foam it acts as a vapor barrier.

 

[squarewav]

What about "Reflectix" insulation?

Reflectix (available at Lowes in the US) is two pieces of metalized film with a polysomething core. It's about 0.3" thick but it looks like it could be pinched if necessary which is ideal for my situation. It comes in a big roll.

I'm thinking I could use foil tape to fasten it to either the exterior wall or the back of the new framed wall. If I can get it behind the radiator that might be a good balance with the space constraints that I have.

 

[Bondo]

Ayuh,.... The reflectix is better than nothin', but havin' a contractor come in 'n spray foam it with closed cell foam is hands down, the absolute Best answer for yer application,....

I'd put the reflectix under the drywall, over the studs,....
Same as where the plastic vapor barrier would be,....

You could also stuff fiberglass behind the heater, 'n fill the bigger bays with foam board,...

 

[squarewav]

What spay foam are we talking about exactly? This is for a 9'x6' piece of wall. I don't know if I want to go through the trouble of renting a foam spraying and all that jazz.

I have seen two-part polyurethane spray foam kits that come in a cardboard box and include a sprayer. But nothing in stock at the local stores.

Also, what is legit for close contact to the radiator? I suspect I probably don't want Reflectix in close contact with anything hot since it is ultimately a plastic film. Ideally I need something that I can just stuff around the back of it. Can I put fiberglass insulation next to it? Or maybe there's a fiberglass insulation that has some foil on one side?