Structural engineer Nathan Charlton on SmartBeam cellular beams

June 01, 2007 |

Manufactured by CMC Steel Products of Rockwall, Texas, SmartBeam castellated beams are an alternative to traditional steel I-beams for roof and floor structures. The beams are manufactured using a standard wide-flange steel beam that is cut in half longitudinally using a circular- or hexagonal-shaped web cut. The two halves are separated, staggered, and welded together to form a beam that is approximately 50% stronger and deeper than the original beam. SmartBeams are ideal for long spans (30 to 50 feet), allowing Building Teams to eliminate internal columns on floors to create flexible tenant spaces.

Nathan Charlton, principal with Seattle-based structural engineer KPFF Consulting Engineers, specified a system of SmartBeams for the $24 million, 195,000-sf Banner Bank Building in Boise, Idaho. The LEED Core and Shell Platinum building was designed by the local office of Omaha, Neb.-based architect HDR.

Why Nathan Charlton specified Smartbeam for Banner Bank:

“Using cellular beams eliminated all interior columns, resulting in a floor plate that, from a leasing standpoint, results in 100% flexibility for tenants.”

“Because the mechanical and electrical engineer could route much of the conduit and piping through the beams, the floor-to-floor height was reduced by eight inches. This reduced the building skin area by 4.8% per floor, which amounted to savings in precast concrete elements and glazing systems.”

“There was no appreciable difference in cost between cellular and wide-flange beams. While cell beams cost more to fabricate, the reduction in interior columns and associated connections offsets additional first cost.”


Nathan T. Charlton Principal, KPFF Consulting Engineers, Seattle

Charlton is a principal with KPFF Consulting Engineers, a Seattle-based structural and civil engineering firm. Since joining KPFF in 1990, Charlton has designed several of the firm's most prominent long-span structures, including the 1.2 million-sf conference center for the Church of Jesus Christ of Latter-Day Saints in Salt Lake City. Other projects include several high-rise condominium projects in Portland, Bellevue, Wash., and Los Angeles.

Charlton holds a bachelor's degree in civil engineering and a master's degree in structural engineering from Portland (Ore.) State University.
Overlay Init