Prosoco air barrier closely tied to Living Buildings

Prosoco R-Guard, Prosoco Cat 5

Living Building Spotlights

The orange layer recently painted onto the exterior walls of the Kendeda Building for Innovative Sustainable Design is intimately tied to another Living Building Challenge project.

Prosoco R-guard, Prosoco Cat 5
Prosoco R-Guard air barrier being mixed at the company’s Lawrence, Kansas. Photo courtesy Dwayne Fuhlhage.

Fluid-applied air-and-water barriers generally perform better than fabric wraps or rigid boards because they can be integrated with fluid-applied flashing and gap fillers to create a continuous seal around a building’s walls.

Kansas-based Prosoco hoped its R-Guard system would be selected as the air-and-water barrier for the Bullitt Center, a Living Building project in Seattle that began construction in 2011. Prior to construction, a consultant for the Bullitt Center told Prosoco sustainability director Dwayne Fuhlhage that the company’s fluid-applied product couldn’t be used on the high-profile building.

At the time, specified Prosoco R-Guard products contained a class of chemicals called phthalates, which are used to “plasticize” fluid-applied materials so that they’re less brittle once they dry and therefore less likely to crack. That’s an important quality for a coating designed to serve as an unbroken barrier that blocks the air movement into and out of a building.

The problem is that some phthalates have been closely associated with cancer and male sterility. They’re so hazardous to human health that they’re among 22 “Red List” chemicals not allowed in Living Buildings.

It was Prosoco’s response to the Bullitt team’s thumbs down that created a new opportunity. The company’s R&D team worked with BEI, which was then Prosoco’s formulary and marketing partner, to reformulate R-Guard on the fly — without phthalates. As a result, the Bullitt Center team could point to another example of the many ways their single project was transforming the market for sustainable building materials.

That market transformation took a more permanent turn a few months after the Bullitt Center’s completion. Fuhlhage says the product’s performance and the reduced worker exposure to harmful chemicals convinced Prosoco CEO David Boyer to keep phthalates out of R-Guard for good. The new formula called for a high-molecular-weight polypropylene glycol — a plasticizer not associated with health risks for manufacturers, installers or building occupants. This R-Guard technology was originally developed for the damp and cool application conditions common to the Pacific Northwest; over time, Prosoco’s R&D group has tweaked the product formulations for optimum performance in other North American climate conditions.

Boyer already had mandated a strong commitment to sustainability at the 80-year-old family-owned company. That commitment fit with the company’s overall market strategy because its high-performance products are particularly popular among LEED projects. While competitors now offer Red List free fluid-applied barriers, Prosoco’s recognition as an early adopter has increased its profile in the growing submarket of healthy, sustainable building materials.

“We could have formulated it just for the Bullitt Center and made it a special order system,” Fuhlhage says. “We opted instead to reformulate for our entire product offering.”

Product basics: Prosoco R-Guard

Manufacturer: Prosoco, a family-owned company based with headquarters and a manufacturing plant in Lawrence, Kansas.

Kendeda Building subcontractor: Metro Waterproofing

Products used on Kendeda Building: R-Guard Cat 5, R-Guard PorousPrep, R-Guard FastFlash, R-Guard Joint & Seam Filler

How it works: Cat 5 is a fluid-applied air barrier, usually painted on with rollers. It’s designed to be used along with FastFlash, Joint & Seam Filler and PorousPrep, which are applied to rough openings, cracks and holes. All four products are chemically similar.

Worth noting: R-Guard barriers have proven well-suited for rainy climates like Pacific Northwest’s, because they can be applied —and even cure better — under moist conditions. Prosoco’s Dwayne Fuhlhage says that should be even more true in the Southeast’s humid climate.

Certifications: Conforms with CALGreen, Declare Label, Fitwell, LEED, Living Building Challenge, LBC Red List and Well.

PHOTO AT TOP: Metro Waterproofing workers apply Prosoco R-Guard air and water barrier via lift. Photo by Ken Edelstein.