Steel Stud Framing in Puna

[kaialoha]

Having built several homes and office/condo complexes on Maui with steel stud framing, I'm wondering why it isn't used more in Puna. I keep reading about moisture problems being the main concern, but doesn't adequate air movement address those problems enough to make steel a viable construction material?

Also, any comments on using Concrete Hardi-backer (the stuff used to line showers prior tiling) as a siding material?

I look forward to hearing from my fellow Punatics ~ ~ ~

Mahalo a Aloha ~ ~ ~

Punanny

[The_Saints]

If you have enough moisture in the interior voids of the wall to corrode the steel framing, then you have enough to grow mold or otherwise rot wood. Moisture is as much a problem in wood structured walls as it is in steel structured walls. With either material, you need follow the proper building practices which keep the moisture out, Such as adequate air movement in exposed spaces, and proper vapor barriers where required.

Instead of the HardieBacker, why not just use a cement fiberboard type siding, like HardiePanel or HardiePlank, which is the same basic material, but is made into lap siding for exterior mounting? This way you are using the lap geometry to avoid the very water intrusion which would rot wood, grow mold, or rust steel.

[Carey]

We have HardiePanel as our interior & exterior walls....We chose it due our aluminum framed house being metric & having extruded lips that would only accept panels of the thickness of HardiePanel

That said...HardiePanel is not an easy choice to work with, compared to many other siding choices, as little things like outlet cutouts will have you amazed.... be prepared to invest heavily in the cutting blades for your choice of cutting tool....

We have had these walls up for a decade & are truly happy with the result...and starting to forget the "joy" of putting them up...

& to your question, given a choice, we have come to truly respect aluminum framing... there were a few houses built in Hilo & Puna in the 70's with this framing & the resilience of this material is something to consider, but the cost today, vs. the 70's would make it a higher end building material today...

[Rob Tucker]

Galvanized steel studs will have little moisture problem. The caveat is that cut ends should be coated with spray zinc. It is the weakest link that will begin to rust eventually. Studies have shown galv. to be effective for 100 years. Studies have shown boric acid (Hi-bor) to be effective for three years. Big difference.

One oft missed negative of steel frame is that it is very thermal reactive. Sun on a wall (or more especially a roof) will transfer heat into the building like a radiator... so some decoupling is advised. Otherwise the framing techniques are basically the same... except screws out perform nails.


I've been using a lot of steel framing over the last twenty years.

[VancouverIslander]

Rob, when you say "some decoupling is advised", do you mean some kind of thermal buffer material between the wall and the galvanized stud?

Me ka ha`aha`a,
Mike

[Rob Tucker]

I would say that the wall is an issue if it is in direct sunlight. So for the walls the issue starts with exposure. Yard trees, a large roof eave could make direct sun on the walls a minor issue. If you have walls in direct sunlight I would recommend applying about 1" of foam sheeting insulation under the exterior skin.

Roof would be assumed to be in direct sunlight more than walls. So I would recommend either sheet insulation on top of the trusses/rafters or strips of non-conductive material (plastic) on the rafters/rafters.

I had a project in Joshua Tree years ago where we did the walls with R-30 ICF. That was our subcontract - ICF walls. It was a HUD job. Later the builder called complaining about the houses being sweat boxes. "What was going on?" Went in with a thermal imaging device. They walls were all cool. The ceiling looked like a fired up radiator. The steel framers installed un-decoupled steel trusses. Anyway, they had to add tons of air conditioning. All the benefits of the ICF were lost to poor thinking on the steel framing.

[MarkP]

Couldn't be worse than a shipping container.

ETA: No matter what you build with I am really beginning to like the idea of an envelope of external insulation. Put the insulation outside the steel and it doesn't matter how conductive the steel is.

[terracore]

Is there anywhere to buy steel studs around here?

[Rob Tucker]

You have to order them from Honolulu except for some real flimsy stuff at Home Depot.

[VancouverIslander]

Thanks for sharing your knowledge, Rob. And those Ag sheds are a great idea.

Me ka ha`aha`a,
Mike