Friday, March 25, 2011

Real Steel

About ten fifteen years ago there was a surge in interest in the use of steel for building homes. A number of builders began to test the waters and things looked promising, however, for a variety of reasons it never caught on. It's a shame as in many ways it's a superior product when compared to wood.

Some of the minor reasons why it didn't catch on had to do with price fluctuation and uncertainty, availability, and inconsistencies in the way building inspectors handled this product. The major reason steel never panned out for residential construction were the carpenters - the guys that had to actually build these structures. Carpenters, and although my job title says project manager I still consider myself a carpenter, are very slow to accept new products and techniques. We've seen thousands of products that were promoted as the next best thing, only to turn out to be garbage, or worse, dangerous. Carpenters also tend to think in terms of what they know and what they can feel, and not in abstract engineering or scientific principles. Steel, and by this I mean the lightweight steel framing that were being used in homebuilding, feels flimsy and weak to a carpenter used to solid blocks of wood. The knowledge that once all the steel is fastened and sheathed, the overall construction will gain strength is not something obvious, despite the fact that lightweight steel has been in use in the commercial construction industry for years.

Not is all lost, however, we still use lightweight steel almost exclusively for finishing basements - steel won't rot or become home to wood eating insects. It's dead straight compared to wood, which 9 times out of 10 isn't. And it doesn't burn. You need some special tools to work with it, but once you master a few easy techniques, it becomes amazingly simple and forgiving to work with. We also make use frequently of heavy rolled steel flanged beams. Laminated wood beams have replaced steel in many instances, however, many times steel is the best choice for a structural beam. At work I deal with steel pretty often, surprisingly often for a residential remodeling company. Steel beams are much smaller than wood beams of the equivalent strength, and steel beams can be supported by steel posts that will fit inside a standard 2x4 wall.

I have included a photo of a small addition my company is building currently. We are opening up 23' of the existing back wall of the house and to support this opening we are using a W10x65 beam. This beam weighs 65 pounds a foot or about 1500lbs. The beam was delivered to the job and placed on the driveway. Two of us moved the beam around to the back of the house and then into the addition and then into place, using only mechanical advantages, 4" PVC pipes, and small hydraulic jacks. You will see me jacking the beam the last few inches.


Steve Watson said...

A guy here built his RR benchwork with steel wall-studs, for reasons of weight, long-term stability, and not requiring noisy rotating blades (and producing sawdust!) to cut. Interesting idea, though I'd want to make very sure no wires could chafe on exposed edges, and ground the whole structure in case one did. It also looks like a bit of a laceration hazard when working underneath the layout.

I think I'll stick to wood when I build mine ;-).

Jim Musser said...

They are light and stable so I could see the plus side to doing that. The wires aren't a big deal as the studs are designed for 120v and higher voltage to be run through them - they make plastic inserts that slide in the prepunched holes to prevent chaffing. Only the cut ends are sharp. I've also heard of heavier angle steel being used - welded or bolted together.