Builder George Cheshire of Spiral Development, in Pasadena, Texas, can't find the skilled trades he needs to build even a conventional house. So, he stopped building conventional houses. Now, he builds with structural insulated panels (SIPs) made from expanded polystyrene sandwiched between durable aluminum skins. (Skins also can be galvanized or stainless steel.)
The panels go together like a puzzle, he says.
Like SIPs that are made with OSB, metal SIPs are factory-built according to the builder's plans. The factory ships the numbered, interlocking panels to the site, where they are snapped together and placed in a c-track that's bolted to the foundation with expansion bolts. A sealant on the seams makes the walls watertight. Window and door openings are cut onsite.
Fred Ballard, owner of Blue Horse Building & Design in Austin, Texas, has worked with Dallas-based Metals USA Building Products' SIPBLOC for 2 1/2 years. He says he can put up the 18- to 20-foot walls of a two-story, 2,700-square-foot house in three days with a three-person crew, compared with the five weeks it would take to frame, insulate (with batt) and apply a moisture barrier to a stick-framed house. Although it costs 2 percent to 3 percent more, his homeowners cut their electric bills in half, he says.
Chris Kavala, whose company, Marquis Construction & Development, in Holiday, Fla., has built with metal SIPs for three years, tells buyers to expect a 30 percent to 50 percent savings in utility bills over masonry block.
Metal SIPs absence of wood also means no structural damage to the home because of termites.