A Tiny House of Metal
Perhaps the best thing about having a blog is the conversation that can come from what began as just a personal thought. Blog posts often have the ability to create bonds and even drive wedges between people who typically do not know each other other than from the Interwebs. And while the results have not been as aggressive, the argument between a tiny house using wood and one using metal has created an ongoing dialogue that has brought to light a number of interesting facts.
I was most recently contacted (via post comments) by Lissa Rasmussen of the Metallbau Group in Portland, Oregon. Specializing in consulting services, shop drawings, and fabrication of wall panels, trusses and components made from load bearing Light Gauge Steel Framing, the group has crafted some impressive structures across the country.
Lissa responded to my post on Who would use wood (for their tiny house)? with fantastic information and a number of points to ponder. She wrote,”
Having been involved in the framing of over 3 million square feet of bearing wall light gauge steel construction, I was interested to see your debate. A few comments:
While steel is more expensive than wood, the straight stud factor is large. (Commercial wood framers are culling up to 30% of the studs they are delivered to get usable material.) With steel studs you don’t have the nail pop issues, or the settling and expansion and contraction that will damage your interior finishes down the road.
Regarding rust, all light steel is G60 galvanized. You can order G90 galvanization which is what they use in Hawaii. You may have to order from a dry wall supply house rather that a big box store or lumber yard. Since you won’t have a great number of studs in a tiny house, if you are super concerned about potential rust, you could spray any cut ends with cold galvanization paint.
Regarding insulation, the best way to reduce the thermal bridging is to apply a 1″ foam board on the exterior of the building (similar to what is used in a commercial stucco application). This has been used in many areas, from North Dakota to Northern Idaho and met the local R-value requirement of the codes.
Regarding labor, since you aren’t experienced with steel, it would be slightly slower, but it is a quick learning curve. You are basically using a screw gun to install the four screws in each stud. The screws are a positive mechanical connection versus the friction connection of a nail and will hold up over travel and vibration much better than the nails.
Regarding grommets, they are very quick to install and just snap in. They are necessary to avoid damage to the wires, but the tradeoff for a non-combustible house is worth it IMO.
Regarding hanging pictures, you just use a screw gun instead of nails and you can easily find the studs with a magnet.
I see comments regarding the reuse of wood and 100 year old barns and I would agree that reusing old growth wood that was harvested 50-100 years ago can be done, but the wood that is sold now days is not old growth and has a much higher moisture content and therefore the mold issues are a real concern.
I immediately contacted Lissa to thank her for adding to the conversation. It is not often that someone in an industry responds to a ‘lil ol blog like mine with informative, intelligent, information, including an invitation for anyone to contact her regarding building with metal.
While Crystal and I are still leaning toward a mixture of new lumber and reclaimed wood, we certainly feel more informed about metal and will continue to welcome any and all comments on any and all subjects!