During the Wednesday afternoon CAMX education session “Opportunities for Composites in Architecture,” an expert panel explored the pros and cons of FRP composites as a building material.
Architects are attracted to composites because the materials enable them to collapse various structures by reducing the layers required with conventional building techniques, says Herwig Baumgartner of Baumgartner + URU LLP. The strength of a composite structure also makes it excellent for wide-span applications. But there are issues, including the public’s perception of the material. Baumgartner’s firm designed a two-story home that included many composite structures, but the clients balked at the prospect at first, saying that they didn’t want to live in a “plastic house.” Once the client was on board, the firm then had to contend with Los Angeles building code officials, who did not make it easy to get the home approved.
Emily Guglielmo, associate and manager of the San Francisco Bay area office of Martin/Martin Inc., a structural engineering firm, noted that it is important for the composites industry to sell their material to people in the building industry. Many don’t understand it.
But structural engineers who are familiar with composites’ properties appreciate their high strength-to-weight ratio. That’s particularly important for the west coast, where lighter-weight structures are preferable because of seismic activity. While a building façade of precast concrete might weight 50 to 75 pounds per square foot, the same design made from FRP weighs only six pounds per square foot.
FRP is also excellent for sculptural applications and for curved applications. “With concrete or steel, the second an architect asks us to curve it, the price goes up and the engineering gets more complex; however, when we take that same form in a composite, the engineering gets simpler,” said Guglielmo. “There’s a nice marriage of architectural intent and structural capacity.”
There are iconic building facades being built with FRP today, including the San Francisco Museum of Modern Art (SFMOMA). But composite materials need more champions, Guglielmo said. A building project that uses composite materials requires an architect who is comfortable creating with the material, an engineer who knows how to engineer it, a contractor willing to build with the material and a municipal building department that is willing to accept it. It’s difficult to be successful when you only have one or two of those parties on board and when you only get an owner every 10 years who is willing to think outside the box.