Advances in plastic formulations and color technology mean vinyl is no longer limited to a staid palette of whites and beiges.
Advances in plastic formulations and color technology mean vinyl is no longer limited to a staid palette of whites and beiges.

Since the 1960s vinyl siding has been sold as an exterior that doesn't need painting. But the color was prone to fading and the material was susceptible to damage from weather or windblown debris. There's reason to criticize some of the early vinyl siding, admits Jery Huntley, executive director of the Vinyl Siding Institute (VSI). She even keeps a collection of siding samples from the bad old days just to remind her of what the industry is trying to overcome. In some cases, those days weren't that long ago, Huntley says. “Even in the early '90s, you had manufacturers printing ‘ASTM D 3679'on the side of the box for product that had never been tested and probably wouldn't pass,” she says. “But that's no longer the case.”

Ninety-six percent of vinyl siding and soffit panels made in the U.S. are now verified through VSI's certification program. Under this program, which began in 1998, an accredited third-party inspection agency works on behalf of the VSI to conduct unannounced factory inspections twice a year and review a dozen performance tests that comprise ASTM D 3679 and D 4477 (siding and soffit panel standards, respectively). These performance standards set limits on thermal expansion and contraction, and measure resistance to impact, wind load, and weathering due to exposure to moisture and sunlight, among other factors. This third party-verification is also demanded by code. The 2006 editions of the International Building Code and the International Residential Code now require that code compliance with ASTM D 3679 be certified through a third-party quality control agency.

Color retention. D 3679 didn't do enough, however, to satisfy customer expectations for a durable exterior, Huntley says. Dark colors in particular, which were prone to fading, were out of the question in a sunny region, so vinyl siding became associated with a relatively bland palette of whites and beiges. Since 2003, however, ASTM standard D 6864 has provided the industry with a consistent method for measuring the degree of color change due to exposure. Changes in plastics technology have allowed a variety of deep saturated colors that can withstand a broad range of outdoor exposure conditions.

Marketing integrity. Because the ASTM standards are performance standards, manufacturers can make vinyl siding panels any way they want. There are no standards for panel thickness or the configuration of the nail hem or the formulation of the plastic. “Manufactures can, and do, take advantage of the range of technologies available to them,” Huntley says, and she indicates that the differences between products are the stuff of which marketing is made. “It's up to each company to tell us why they're different from the competition. We just want them to be honest about it,” she says. For this reason, the VSI certification program also includes a review of the manufacturer's marketing literature to verify that products are what manufacturers say they are. “It's important that the products meet basic performance standards. But it's just as important that manufactures demonstrate their integrity,” Huntley says.

Installation standards. Of course, consumer confidence in the long-term performance of vinyl siding does not rest on the manufactures' shoulders alone. ASTM has also defined good installation practice in ASTM D 4756. This installation standard is consistently cross-referenced in the D 3679 manufacturing standard so that, for example, the installation requirements covering the type, size, penetration, and minimum spacing for nailing off panels is the specification used in the wind-load performance testing.

But like the manufacturing standard, the industry has, until recently, lacked any kind of assurance program. To this end, VSI established a Certified Installer program last year, aimed first at training enough trainers and then at training all installers in the procedures laid out in the ASTM D 4756 standard.

To be effective, VSI had to offer hands-on training; so far, 700 vinyl siding installers have been certified in 40 states, Huntley says. “To be meaningful, it has to be a local effort. But that's exactly what makes it slow to ramp up,” she says, explaining that April through October is the busy season when not many installers are interested in training. Huntley is confident, however, that VSI will have trained a total of 1,400 certified installers in all 50 states by the end of this coming winter.