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A Complex Insulation Project

Long Tab Banded insulation system meets code for climate-controlled environments

Therm All Casestudy Jan18

When it came time to select an insulation system for the brand new WestWorld of Scottsdale North Hall, Dan Barnett of Arizona Corporate Builders, Tempe, Ariz., was faced with a difficult decision. The North Hall, which boasts 117,000 square feet of climate-controlled event space in Scottsdale, Ariz., is a unique structure.

“We needed something that, first and foremost, met the energy codes mandated by the city of Scottsdale,” says Barnett. “The other key criteria was purlin exposure—we needed a roof system that allowed the purlins to remain exposed, as there are over 1,000 purlin attachment points on the building."

This meant ruling out Banded Liner Systems, which are often used to meet code for climate-controlled environments, because the fabric vapor retarder in the system covers the purlins. “Knowing that this was a unique project, I turned to Rick Bachman [district manager] from [North Olmsted, Ohio-based] Therm-All to advise us on which insulation system would be best,” notes Barnett.

Barnett and Bachman worked together on an earlier portion of the WestWorld project, the 120,000-square-foot Tony Nelssen Equestrian Center (TNEC) Equidome. “That was a large project,” Barnett says. “To give you some context, the roof of the Equidome supports four, 50,000-pound air handling units.” The Equidome was retrofitted with a single layer of R-30 fiberglass insulation in the roof and R-25 fiberglass in the walls, both with a Gymguard vapor retarder from Lamtec Corp., Mt. Bethel, Pa.

It didn’t take long for Bachman to select a Long Tab Banded insulation system for the North Hall roof. “When a job requires purlin exposure and the building needs to meet code, Long Tab Banded is a clear choice,” says Bachman. “The system blends the thermal performance of High-R insulation with the convenience of being able to access the purlins.”

Long Tab Banded insulation systems—also commonly referred to as High-R Banding or Long Tab with Banding, meet the definition of a Filled Cavity (FC) System in the latest ASHRAE 90.1 standard. The core system consists of metal banding, two layers of fiberglass and a vapor retarder. The metal banding is installed first, perpendicular to the purlins, and acts as the support for the fiberglass insulation. Once the banding is complete, the first layer of fiberglass is installed. This layer is laminated to a vapor retarder, which is exposed to the interior of the building, and installed between and parallel to the purlins. The final step includes installing the second layer of fiberglass, which is unfaced, perpendicular to the purlins.

“The fact that the purlins are exposed in a Long Tab Banded system means an easy installation of electrical, mechanical and other systems,” says Bachman.

Bachman was also tasked with selecting a vapor retarder that would not only perform well, but also photograph nicely. “We knew that the North Hall would be home to many televised and photographed events,” says Bachman. “For this reason, aesthetics factored in heavily when selecting the right vapor retarder.” The team decided on a black WMP-50 exposed vapor retarder from Lamtec Corp., Mt. Bethel, Pa.

Getting the North Hall project off the ground was no easy feat. Mike Bode of Phoenix-based Castle Steel notes that erecting the roof alone was a complexity that required many meetings with Castle Steel’s engineer, erection crew, and the crane supplier. “We built the roof on the ground and then installed it,” Bode says. “We used one 500-ton crane and one 300-ton crane on-site to raise the roof in pods, or sections.” Bode’s crew installed the roof in seven clear span pods. Because this was such a large-scale project, “We added extra bracing to the rafters for additional reinforcement during the section placement,” he adds.

A standout architectural feature of the project is Manchester, N.H.-based Kalwall’s endwall on the north side of the building, which was pre-set to be 4 feet on-center. All other girts were designed to be 5 feet on-center.

The project wasn’t without its complexities, but it certainly proved to be a rewarding challenge for all parties involved. “You walk into the space and it’s just phenomenal,” says Bachman. “The sleek, black vapor retarder, the clean, finished appearance of the entire system—it took many folks and a lot of coordination to get it to this point, but it was well worth it.” Bode agrees, stating, “We are proud of this one.”

Bridget Mahovlic is the marketing specialist at Therm-All, North Olmsted, Ohio. To learn more, visit