General contractor Tom Silva notes that the R values of individual panels are only part of the story. "The real benefit of SIPs is that there's no break in the insulation," he says. "In typical framing there's a stud every 16 inches in the wall, and the R value of a stud is lower than the R value of the insulated walls beside them. You add up all the studs in a wall, and that lowers the R value of the wall overall."

Baker agrees. "With SIPs there's nothing given up to framing members, just a spline every 24 feet as opposed to a stud every 16 inches, and there's none of the lumber around windows and doors. The difference in performance is really dramatic. With gas headed for $50 a barrel and natural gas going up even more, that's going to be a bigger and bigger issue."

Panel construction isn't a new technology, but the oil embargo of the 1970s gave the industry a boost, and by 2002 there were more than 12,000 new homes a year being built with SIPs. As August 2004 drew to a close, we were pleased to count the new ell and master bedroom extension at Carlisle among this year's SIP totals. We used panels for the new barn floor, too, taking advantage of their superior strength to span its wide distance. Baker says that's not an unheard-of use of his panels, which are more typically used for walls and roofs.

"We've seen our panels used as flooring when there's a need for insulated floors—where you have living space over an unheated garage, for example, or in coastal regions, where homes may be built on piers," he says. "And we've seen them used in applications like the barn at Carlisle, where they can span greater distances than you could cover with traditional framing." Tom notes that the 40-foot-wide floor in the barn is supported by a trio of LVL (laminated veneer lumber) beams and support columns every 12 feet in the garage underneath.

Ask TOH users about Insulation

Contribute to This Story Below

    More in Framing & Insulation