Spray Polyurethane Foam Shows Versatility in Opryland Renovation Project
Location: Nashville, TN
During the recent renovation of the Gaylord Opryland Resort and Convention Center, spray polyurethane foam (SPF) was used in two different applications to solve unique problems. The first involved insulating a number of guest room walls with CertainTeed's CertaSpray® Closed Cell Spray Polyurethane Foam Insulation. The second utilized the structural properties of CertaSpray Closed Cell to help create a new bar and lounge in the Cascades Atrium.
EXTERIOR WALL RENOVATION
Renovation of some guest rooms required removal of both the fiberglass insulation and the exterior fiberglass mat-faced gypsum board sheathing, leaving exposed brick. Replacing the exterior sheathing would have required removal and replacement of the brick, an expensive proposition. As an alternative, the general contractor – Insulation Solutions of Tennessee – developed the idea to use closed cell SPF with a baffle system.
The baffle system provided an air gap for the drainage plane while also serving as a surface for spraying that transferred loads on the brick back to the studs. The baffle was test sprayed prior to installation to ensure it would have good adhesion. Two inches of closed cell SPF were then applied directly onto the baffle, solidifying the wall system and adding strength thanks to the foam's adhesion and structural rigidity. The foam provided a thermal insulation of R-13 and served as the air barrier. Finally, the wall system was finished on the interior with drywall.
CASCADE ATRIUM'S FOUNDATION RENOVATION
The renovated Gaylord Opryland's Cascade Atrium also features closed cell CertaSpray. The new bar and lounge, known as The Falls Bar, presented some unique challenges. In designing this area, the general contractor found the existing concrete foundation would be unable to support the bar's weight. Polystyrene was considered, but there were concerns over it settling under the weight of the structure.
"With assistance from CertainTeed's Building Science Group, the team became convinced that closed cell SPF would be able to support the dead load and anticipated live loads of the bar area," said Lionel Rossignol, product manager, CertainTeed Insulation. "Additionally, its use would significantly reduce the dead load upon the existing concrete pad."
The foundation was designed as a waffle grid of concrete channels with SPF in-between. To form the channels for the concrete, expanded polystyrene (EPS) boards were covered with polyethylene sheeting, one of the few materials SPF will not adhere to. The boards were cut to form the grid in the foundation, into which concrete would be poured. This process required significant detail work to deal with the curved structure and all the pipes and conduit running in the foundation. Once the EPS board grid was formed, 14 inches of closed cell SPF was sprayed into the grid pattern in multiple passes of two to two-and-a-half inches each. Spraying the foam in thicker passes can cause it to overheat from the exotherm and become dimensionally unstable.
Once satisfied that the foam was of acceptable quality, the polyethylene sheeting-covered EPS boards were removed leaving a waffle grid of channels. Concrete was then poured into the channels to complete the structure. The result was a lighter weight foundation for the new bar and lounge that did not require the existing concrete base to be replaced.
The two jobs, totaling 64,000 building feet of SPF, were completed during July and August 2010. CertaSpray closed cell SPF was critical in addressing two difficult situations that otherwise would have required costly, time-consuming solutions.
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