metal studs on exterior

Hi gang,

As I sit and ponder the meaning of life and SIPs I still have to wonder a bit given their premium price. Not that having such good insulation value is a bad thing, but has anyone ever given thought to a metal studded exterior system like commercial buildings?

Slap up some drywall on the exterior of the TF with just enough screws to hold it into place. Add some vapor barrier. Then add the metal stud system outside of the drywall. Easy to work with and cost is better than lumber.

Add wiring, insulate, add exterior sheeting if required. Inside of house screw drywall to metal studs etc.

Would be cheaper than SIPs and wood framing, yet able to go up quick due to the light weight of the materials.

Thoughts?

we did a house this way, but using wood studs.
One disadvantage was that the wall components are exposed to the weather. This was mostly a problem when waiting for the electrical inspection.....we also had a scare with a thunderstorm after the insulation was in place.
Can be done though. I can also say that that house is well insulated and comfortable. The walls were 6" fiberglass and the roof was 10"
-Mark in ontario.

I worked on a job where we used horizontal nailers and spray foam on a building and it worked great. Didn't need vapor barrier, as the foam is the barrier, really tight building now. Got the idea from a timber-framing friend. They hung the drywall on the posts, put horizontal studs on, screwed drywall to the studs, wired the place and foamed right over the wiring after inspection. Much like in the horizontal nailer system in Tedd Benson's 'The Timber-Frame Home' but with the added efficiency of spray foam.
Mark

Any ideas on price for spray foam?

Anyone besides myself wondering about how well metal studs in an exterior wall will conduct heat out of the building?

I think it will be less than wood and am not too concerned about it given the majority of commercial buildings use metal studs, though may use styrofoam.

I will research some more in the next month or two.

Actually metal studs conduct heat at a greater rate than wood. There was an article in Fine Homebuilding some years ago exploring this technology and I remember it being mentioned that some contractors of stick frame buildings were doing hybrid const consisting of wood stud ext walls and metal stud int. Specificaly to deal with the heat loss issue of the metal studs.
One option I have wondered about is using metal studs with a thermal break. That is with a layer of rigid foam either over ply sheathing or directly on the studs then strapping and siding.
Or alternatly the same idea using 2x4 wood studs