Crown Jewel of Portland Airport Expansion is Mass Timber Roof

The undulating edge of the roof will become the cursive signature of the airport, if not the whole city. The TCORE, or Terminal Core Redevelopment project, will see the main terminal transformed into one giant space with picture windows and round skylights, filled with live plants and a ceiling decorated with a lattice of woodwork.

The new terminal roof is being assembled right now, just across the airfield. It will be taken apart and installed in pieces in summer 2022 while the airport operates beneath it.

On a tour of the construction site on Oct. 20, the scale of the new building became apparent. While the steel girders to which the glue-laminated (glulam) beams are connected are now only 13 feet off the ground, the 392,000 square foot roof will peak at 54 feet high when installed. The massive structure is built in 20 modules or “cassettes” that fit together like slices of bread, each 120 feet by 110 feet.

The glulam beams were manufactured in Eugene by Zip-O Laminators. The beams toward the edges of the structure have a scallop shape cut in them, but the lines of the planks are relatively straight. The roof, however, bulges in the middle to a dome shape. There, the lines on the glulam beams have a considerable curve to them, where the packed-together strips of wood have been bent into shape.

For computer numerical control (CNC) profiling, the beams went from Eugene to Timberlab, a Swinerton company in Portland, for computer numerical control (CNC) profiling. This means robotic routers were used to shape the edges of the beams and drill holes for the metal connectors that attach the glulam beams to the steel structure. The Hoffman-Skanska Joint Venture is the general contractor.