Most innovative skylight application
Super Sky Products, Mequon, Wis., designed and manufactured two vault skylights for the Los Angeles County Museum of Art’s three-story structure. Each skylight measures 74 feet by 116 feet, 8 inches. The oversized glass lites slope into special welded stainless steel gutters that are concealed in the building walls.
The glass itself consists of insulating glass units from Viracon Inc., Owatonna, Minn., consisting of 3/8-inch VE13-2M low-E, Starphire heat-strengthened with high opacity white silkscreen on the no. 2 surface; a 1/2-inch air space with mill spacer and black silicone edge seal; and 9/16-inch Starphire heat-strengthened laminated glass with a .060-inch clear PVB interlayer.
“This skylight, designed to fit around an unusual structure with minimal visual impact, resulted in an impressive visual appearance that resembles a glass ceiling more than a skylight,” says Tammy Schroeder, Crystal Achievement Award judge and marketing specialist for Linetec, Wausau, Wis.
The skylight system is hung from an exterior steel truss system with tension rods and stabilized laterally with stainless steel cables from Ronstan International Inc., Alameda, Calif. The skylight frame also makes provisions to support the sprinkler system and conceal track lighting on the underside of the skylights.
“Glazing the skylight was probably the most challenging part,” says Curtis Groeschel, project manager. “It wasn’t possible to sub-assemble a section of frame and then square it up as we’d typically like to do, because everything had to be hung from the steel structure above with pre-installed steel rod assemblies.” The glass had very tight tolerances to the skylight frame components in order to maintain the system sightlines, and those lites were 5 feet by 9 feet and weighed 450 pounds. Each of these large lites was set by crane, through a web of diagonal rods bracing the steel structure. This required some very careful maneuvering of the glass and some special crane work because the skylight was concealed behind walls and under the steel structure. “Our installers [Precision Sky Erectors of New River, Ariz.] did a great job of minding all the tolerances involved to set very large lites of glass in a complex frame system,” he says.
The node connections had to be unique as the custom skylight system had to meet specific criteria at those points as well as special conditions around the perimeter. These included: attachment to vertical rod, clamp to exterior east-west cable, clamp to interior north-south cable with the cable concealed in skylight mullions and clearance for an electrical conduit to pass through the joint on the interior in an east-west direction. The system also had to channel moisture around the node assembly while concealing all components within skylight members with the 2 ½-inch-by-4 ½-inch sightlines specified by architects Renzo Piano Building Workshop, Paris, and architect of record Gensler Architecture, Santa Monica, Calif. Ishler Design and Engineering Associates, Santa Monica, Calif., engineered the system, and Matt Construction, Santa Fe Springs, Calif., was the general contractor.