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By Nancy B. Solomon, AIA

One of the beauties of fiberglass is that a complex element can be built and trucked to the site as one assembly. In the case of the Florida project, which began construction in September 2003, the single stairs component will measure approximately 26 feet horizontally, 3 feet 21¼2 inches wide, 9 feet 2 inches vertically from lower to upper floors, plus another 3 feet high for the guardrail, which curves up from the treads and landings on the north, south, and west sides of the staircase and bends yet again into a handrail. Thickness at the risers and treads will be about 1 inch. “To accomplish the same thing in steel would have taken several hundred pieces welded together,” says project architect Dwayne Oyler. “This will look like one piece that has been folded and bent the way we needed.”

The architects are forgoing fiberglass’s integral nature, however, on the east side of the stairs, where they have proposed a series of thin fiberglass rods spaced 4 inches on center and extending to the roof to form both a guardrail and translucent screen. These nonstructural elements will be attached to the body of the stairs with custom metalwork.

The structural carriage will be supported by four stainless-steel beams—two under the upper landing and two under the lower landing—that cantilever out from building. All of the fiberglass will be painted with the epoxy primer and urethane topcoat typically used for boats. To create good slip resistance, the topcoat on the treads and landing will be mixed with nonskid plastic beads.

Testing mechanisms for fiberglass have long been in place in the boat-building industry, so the designers could rely on their results to determine the code-related characteristics of the material. For example, explains Mori, “Water stresses can be translated into gravity and wind.” Equipped with such information, the designers had no trouble getting approval by the local building department, despite the fact that fiberglass is an unconventional structural element in architecture.

The cost of fiberglass is greater than the other alternatives—wood, concrete, and even stainless steel. But Mori suggests that, when considered over its lifetime, this up-front cost may even out when weighed against ease of maintenance.