Fiberglass architectural elements restore Ferry Building

In a city filled with memorable landmarks, perhaps the most enduring is San Francisco's Ferry Building. A recent $90 million refurbishment included fiberglass architectural elements fabricated by Kreysler & Assoc. (American Canyon, Calif., U.S.A.)

Completed in 1898 as the passenger terminus for the bay's ferry routes, the steel-framed structure with its 240-ft tall clock tower survived major earthquakes (1906, 1989) and the great fire of 1906. As cars replaced ferries, the building was rendered obsolete. Its beautiful interior concourse was lost to construction of office/retail space in the 1950s, and the Embarcadero Freeway, built in 1957, obscured its facade. But, car-weary commuters revitalized ferries in the 1980s, and when the Embarcadero - irreparably damaged by the 1989 earthquake - was torn down, the building's re-emergence stirred interest in preserving it for adaptive reuse.

The central nave, with arched steel trusses and 660-ft skylight, was reopened by removing the 1950s-era interior office walls. However, 11 of the decorative terra cotta brick arches that surrounded half-moon windows had been destroyed, together with moldings, column capitals and bricked panels surrounding higher clerestory windows. While similar bricks were available, the cost in labor, time and added support structure was prohibitive.

Kreysler & Assoc. created foam-and-plywood patterns to imitate the terra cotta bricks, gluing sand to the foam for grout lines. Fiberglass female molds were made from the patterns. Molds were sprayed with colored isophthalic polyester gel coat from Valspar Composites (Elkhart, Ind., U.S.A., select 239), followed by lay up of 1.5-oz glass chopped strand mat from Owens Corning Composite Solutions BusinessSaint-Gobain Vetrotex America (Valley Forge, Pa., U.S.A., select 240) and strategically placed woven fiberglass fabric from Owens Corning (Toledo, Ohio, U.S.A., select 241) for added strength. Part layups were wet out with fire-retardant polyester resin from Eastman Chemical Co. (Carpentersville, Ill., U.S.A., select 242) and ambiently cured. To simulate the patina of the originals, the fiberglass faux bricks were sandblasted to remove the gel coat's gloss, then hand-painted with acrylic stains. Kreysler's "flex-anchors," thin metal rods co-molded within the laminate, were then bent and welded to standard metal studs, leaving a gap, which allowed for the different coefficients of thermal expansion (CTE) of the fiberglass, the studs and the building itself. The restoration team, including Kreysler, did similar work on San Francisco's Flood Building (see CT July/August 1996, p. 20).