For instance, measurement tolerances can be a problem so McDonough allows for a 1/8-inch expansion gap. “There is a lot of unexplored design potential for SIPs, so I like experimenting with it.”ON THE HORIZON
At the moment, production home builders are not convinced that SIPs offer design potential and cost savings. This isn't surprising, most manufacturers and architects say. “Builders do not like to change the way they do things,” says Doug Anderson, sales manager for Winter Panel. “They look at panels as a wild and futuristic technology.”
But SIPs have piqued Pulte's curiosity. Three years ago, the Bloomfield Hills, Mich.-based builder constructed a pilot plant in the Detroit area to investigate the viability of building large numbers of homes with SIPs. “They found that if they made some changes, SIPs could work,” Bryan says. “They decided to build another plant in Virginia and they expect to churn out about eight houses a day.”
The importance of Pulte's presence cannot be overstated, says Insulspan's Baker. The builder's success is seen as a vitally important step in the widespread adoption of the technology.
This story first appeared in RESIDENTIAL ARCHITECT magazine.
Keep in Mind
DESIGN LIMITATIONS: The belief that panels limit design options is not true, manufacturers say. Companies such as W.H. Porter make panels to specs. The panels work in conjunction with roof trusses, floor systems, and any other building product it takes to build a home, so anything is possible. One caveat: When ordering windows and exterior doors, a finished window jamb of 5 1/16 inches after drywall is installed will be needed. Check with your supplier to see if there is any additional cost.WIRING DIFFICULTIES: Wiring is typically done through chases in the wall that are 16 and 45 inches off the floor. M. Scott Ball, co-executive director of the Community Housing Resource Center that built a SIPs home, says, however, that electricians often encounter difficulties when pushing wire through the spaces. One solution is to use a heavier baseboard and run wires behind that. In addition, manufacturers recommend using vertical chases spaced every 4 feet. The electrician then simply drills access holes through the floor behind the walls.LIMITED ROOFLINES: Some builders say complex roofs are hard to do with SIPs, but the industry says this is a myth. Dormers are actually easier to build with panels, Bill Wachtler of the panel association says. Complex roofs may take more planning because it is a different process, but they go up a little faster with panels than with dimensional lumber, he contends.CAD DRAWING: Architect Peggy Duncker says that the construction of her house was great once the panels arrived on the site. The shop drawing process, however, was tedious. Any unusual designs can cause problems if they are not checked. The Dunckers' house features different window head heights. Her advice: Check shop drawings carefully before the panels are manufactured.SPLINES: Panels are manufactured with strict tolerances of 4-foot widths and are connected with wood splines. Ball says dimensional lumber splines invariably warp, which makes it hard to notch the connections. That's why he prefers laminated veneer lumber splines. “They are perfectly straight,” and more stable, he says. Another way to counter this is to add 1/8 inch allowance in measurements, says architect Michael McDonough. “It's a good trick for when you are putting them in,” he says. “They will fit much better.”—N.F.M.Resources
Structural insulated panels (SIPs) offer some benefits over stick framing, but architects and builders familiar with the technology say there are some things you need to watch.
Architect Michael McDonough
Community Housing Resource Center
Structural Insulated Panel Association