When Harmon, Ltd., a major curtainwall design, fabricator and installation firm in Walnut, California, was awarded the window wall work involved in the construction of the International Terminal at San Francisco International Airport, the firm turned to Tremco's Glazing Systems Group of assistance.

Specifications for the curtainwall system called for it to withstand two levels of lateral movement as a result of seismic drift. The maximum probable earthquake movement required the wall system to withstand 1-1/4" to 1-1/2" drift with no failure or deterioration. The maximum credible earthquake movement was identified as a 2 to 2-1/2" drift, while requiring no structural failure or deterioration, allowed for sealant failures, gasket disengagement, and minor deformation of connections and metal framing sections may be expected.

Harmon, Ltd. Project Manager Kevin Mannen said, "The use of the Tremco gaskets in this curtainwall system saved us money in the field. The design was unique because the double gasket system used, allowed for the panels to be put in fairly quickly. Most other systems require a lot more field caulking. The bottom line is that the cost of sealants and the cost of labor would have been higher than the cost of the Tremco gaskets used here."