With the cost of lumber soaring, many homebuyers and builders are considering another option - steel-framed homes.
Thanks to the spotted owl and a moderate resurgence in home building, traditional "stick-built" houses are becoming less affordable.The increased popularity not only is because of the price, but also because steel framing is fire-resistant, termite resistant and stronger.
"With steel, we have a house that is lighter, stronger and earthquake resistant," said Russ Robinson, sales manager for Engineered Homes, Lehi, Utah County. "Because the steel is galvanized, there's no dry rot, no termites, no shrinkage, no warping and no knots to contend with." He said steel has six or seven times the strength of wood but only one-third the weight.
However, problems with steel framing have surfaced.
"Carpenters are reluctant to put down their saws and hammers and work with steel," said Kraig Robinson, president and founder of Engineered Homes. "But we now `panelize' the exterior walls, the floor joists and roof trusses and transport them to the job site." He said this process, which his company has been doing for the past three years, not only saves money, but the quality of the work can be better monitored as well.
"We also spray a polyurethane rigid foam called `Corbond' into the wall cavities for a high R-value."
However, another criticism of steel-frame houses has been the difficulty of effective insulation.
"Steel frames are highly conductive of heat and cold," said Jerry Zenger assistant director of the engineering experiment station at the University of Utah. "The metal also has a detrimental effect on the insulation immediately surrounding the steel. This is called `thermal bridging.' The installation of metal studs can reduce the R-value of the (steel-studded) wall insulation by half."
He said when the original test results were revealed showing the extreme heat loss, "everyone was really surprised. The thermal bridging `short-circuits' the insulation." He believes more testing is needed for homebuilders to make intelligent decisions.
"As far as I know, the problem has not yet been solved and should be of great concern to metal-stud producers, users and buyers," Zenger said. "In my opinion, at this time, the single disadvantage of thermal bridging outweighs the advantages, of which there are several."
Bill Brown, senior researcher at the Institute for Research in Construction, National Research Council of Canada, Ottawa, acknowledged that thermal bridging is a problem and shouldn't be ignored.
"You could probably get away with it in Southern California or Florida," Brown said. "But not in northern United States or Canada." However, unlike Zenger, Brown believes that installing a polyurethane sheeting on the exterior of the steel studs can solve most of the thermal problem.
"I wouldn't use less than an R-5 (1 inch) insulated board, like Styrofoam," he said. "The insulating sheeting should do what it's supposed to do."
Brown advises potential home-builders to investigate all the pros and cons, including the costs of using steel vs. wood framing, and make a decision based on the best value.
Zenger, however, would like to see some more testing. "There's some concern that even with the exterior sheeting, if it really cuts it (thermal bridging). I'd like to see some verification."
Russ Robinson, Kraig's brother, said preliminary tests have indicated that exterior foam boards along with polyurethane foam are "alleviating the thermal-bridging problems." He said tests are ongoing and his company is keeping abreast of the latest results.
"None of our homeowners have had any complaints," Robinson said. "They've been telling us how much lower their utility bills have been." He said, however, "The jury's still out."
Rick Haws of the American Iron and Steel Institute in Washington, D.C., said the main advantage of steel-frame homes is price stability.
"In July of 1993, lumber was selling for $295 per 1,000 board feet," he said. "In January of 1994, lumber was selling for $510 per 1,000 board feet - an all-time high. That can add $10,000 to $12,000 to an average home."
He said because of the "plasticity" of steel-frame homes, they can resist earthquakes much better than wood homes. "Steel-framed homes also are fire resistant," he said. "This could possibly reduce residential fire insurance."
The price of a steel-frame house is comparable to a wood-frame home, according to Kraig Rob-in-son.
"If you compare apples and apples," he said, "steel-frame houses are a better value because they're engineered for superior strength and cost about the same as wood houses."
Russ Robinson said all of the steel his company uses is manufactured in the United States and contains 60 percent recycled material. "We're doing our part in this ecology stuff," he said.