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Engineered Wood Formwork is Cost-Effective, Customizable for Apartment Buildings

Affordability was a primary factor for Rush Commercial when making the concrete forming product selection for the construction of the Pacifica Apartments in Tacoma, Washington.

The two-building, 230,000-square-foot apartment complex featured 177 units, two underground parking garages, and required 7,000 yards of structural concrete – including five post-tensioned reinforced concrete decks with up to 800 cubic yards of concrete in each.

It wasn’t unfamiliar territory for the Washington State developer-contractor, which has built, owns and leases over one million square feet of commercial office space and 1,700 multi-family units. Rush Commercial selected 3/4-inch MDO (Medium Density Overlay) plywood for the concrete formwork. Superintendent Bob Bowman says key considerations were cost-effectiveness and how easily the panels could be to cut to size for use as fill-in formwork.

“There were many steps in the wall elevations and many different column block-outs on the exterior walls,” says Bowman. “Wood panels were the most cost effective for the formwork because we could cut and modify the panels to fit as needed. Then (after the concrete was poured) we would cut and modify the panels again to use in others areas.”

Engineered Wood ShapesEngineered Wood Shapes Washington State History

A dramatic series of eleven, 55-foot-high reinforced concrete arches accentuate the façade of the Washington State History Museum.  Built on a prominent site in Tacoma, Washington State, USA, the building is adjacent to the Union Station, a former railroad station, built in 1911. The goal of the Washington State Historical Society was to construct a world class facility, while maintaining the historic architecture of the former railroad station.

The construction team built a 6,800-square-foot gang form composed of APA trademarked HDO plywood panels to form a single arch. Over 4,000 sheets of HDO plywood were used to create sections of gang forms. Panels were reused seven times while pouring the other arches.

HDO plywood panels, like the ones used in constructing the gang forms for the History Museum, have a hard, slick, semi-opaque surface of thermoset, resin-impregnated material that forms a durable, continuous bond with the plywood.