A quarter of a century ago, during a typically frigid winter on the Maine coast, two partially completed structures weathered the storms and icy temperatures quite well. And, much like the lighthouses that dot this craggy shoreline at the family resort of Old Orchard Beach, south of Portland, the buildings shone a light on something significant-in this case, the beginnings of a new way to construct commercial and residential properties.

Pat Huempfner proudly remembers that time in late 1984. Then a just-hired sales representative for Georgia-Pacific’s Gypsum Division, Huempfner recalls that the two condominium projects-five- and seven-stories tall, respectively-were the first installations of a new fiberglass mat exterior sheathing.

“Every gypsum company was looking for a way to avoid all of the issues related to paper – mold, moisture, warping and delamination,” says Huempfner.

Indeed, at the company’s testing laboratories on the opposite coast of the U.S., near Portland, Ore., researchers were making new discoveries. They fashioned a technology whereby a gypsum core could be effectively wrapped in a fiberglass mat and embedded in the core, eliminating the need for gypsum panels with paper-faced mats. Traditionally, gypsum panels were produced by encasing a slurry of calcined gypsum plaster with paper facings. “By every indication, it looked like it would work great,” recalls Huempfner. “But we needed to field test it to be sure.”

Artic Exam

Enter Sto Corp.: The EIFS manufacturer was eager to find an improvement on traditional paper-faced gypsum sheathing. This was particularly vital in cold-weather environments since the final coating on an EIFS system requires that the ambient temperature be above 40 degrees Fahrenheit.

“It was October, and Sto had two under-construction projects on Old Orchard Beach that would be exposed to cold weather for about six months, because it was too cold to finish the EIFS job,” explains Huempfner.

Two other under-construction condominium projects, also on hold for the winter, were nearby. Those had been built using paper-faced exterior sheathing. So, while G-P Gypsum was field testing its products, company representatives had the opportunity to compare its performance-side-by-side-with the technology it hoped to replace.

“We were going to get six months of snow, rain, ocean salt and wind-we couldn’t have asked for a better test,” says Huempfner.

Despite bracing winds and sub-zero temperatures, the then-unnamed exterior sheathing performed impeccably on the two condominiums.

“Six months later, when winter was over and it was warm enough to finish the EIFS, our panels held up beautifully,” says Huempfner. “Not one of them had to be replaced.”

But what of the other two under-construction condominiums, which had left paper-faced gypsum panels exposed to the harsh Maine winter? More than 50 percent of those panels had to be replaced, recalls Huempfner-and, of course, this time they used the still nameless Georgia-Pacific product.

New Markets

Tom Remmele, now technical director for Sto, is also grateful for the work done to introduce fiberglass mat gypsum sheathing into the market as a substrate for EIFS.

“The early work done by Sto and Georgia-Pacific to marry the two products together formed the basis for many years of successful installations,” says Remmele. “We continue to specify fiberglass mat gypsum today as a substrate for Sto EIFS.”

Bolstered by the successful Maine test, Georgia-Pacific launched the industry’s first fiberglass mat gypsum panels: DensGlass sheathing in 1986. Over the next year, Huempfner and a small team of salespeople successfully sold architects, specifiers and contractors on the benefits of the product.

“Our Maine testimonial was a great selling tool,” recalls Huempfner. “Sure, we listed all the attributes-that it didn’t delaminate, warp or sag; and that it was also moisture-resistant and fire-rated. But all they needed to see were the slides I had of those first installations on Old Orchard Beach.”

Ten years later, while on business in the area, Huempfner and a colleague returned to Old Orchard Beach to see how the condominiums that had first used DensGlass sheathing were holding up. He was not surprised to learn that nothing had changed in a decade.

“We spoke to one of the owners, and looked closely at the structures,” he recalls. “The buildings looked great.”