In 1998, Columbus, Ohio–based Exterior Portfolio by Crane attached rigid foam insulation to vinyl siding and launched a whole new product category: insulated siding. The industry said the new product would improve the looks and performance of the most popular siding in the country. “Aesthetics is probably the No. 1 benefit,” says Jim Ziminski, vice president and general manager at Crane. “We can produce boards with a wider exposure. Plus, it allows installers to create straighter walls because, unlike regular vinyl siding, insulated products do not follow the contours of an uneven wall.” A better-looking product is only the beginning, the industry says. The layer of foam creates a product with an R-value from 2.5 to 3, which is relatively low but better than vinyl alone. This makes the product more energy efficient, says the Vinyl Siding Institute (VSI), a Washington-based trade association of manufacturers and suppliers.
Six years ago when Builder wrote about insulated siding, some manufacturers believed that the product could end up being a niche category because of its price premium (50 percent higher, in some cases) compared to traditional vinyl. The price has not come down, but manufacturers say they have made improvements. “We are now using a different foam,” Ziminski explains. “We used to use EPS foam, but now we are using a molded foam and are adding air and drainage channels that help performance.” A different adhesion process also results in a better connection between the foam and siding.
These days the trend toward green building has resulted in renewed interest in insulated siding. “Government agencies acknowledge the ability of rigid or board insulation to improve the energy efficiency of homes,” the VSI writes in “Insulated Siding as Home Insulation,” a guide to help educate builders, remodelers, and raters interested in the product. “Research shows that construction techniques and/or material applications of rigid or board insulation, including insulated siding, reduce the ‘thermal bridging’ effect, or energy transfer through framing members and/or other conductive building materials.”
The industry is also being buoyed by code changes and green building programs that are forcing builders to improve the energy efficiency of their homes. “The EPA includes insulated siding under Energy Star Qualified Homes Version 3 as an option in its checklist of building products or methodologies for a new home to earn the Energy Star label,” says Jery Y. Huntley, president and CEO of VSI. “The use of insulated siding can help achieve up to three points under the current LEED for Homes program, which doesn’t recognize a lot of cladding products.”
To determine the siding’s effect on a home’s energy performance, the industry has undertaken a study with Schenectady, N.Y.–based Newport Ventures. Preliminary results show improvements in air sealing using blower door tests and reductions in thermal bridging using imagery, VSI says, but the final results will not be released until later this year.