St. Edward Catholic Church lacked the funding to build the elaborate Gothic cathedral that parishioners envisioned for its 20-acre campus in Keizer, Ore. But their prayers were still answered when DiLoreto Architecture, in Portland, Ore., employed a series of structural glulam arches to help meet their $4 million budget for a 12,000-square-foot contemporary Gothic-style church.
DiLoreto focused on the essential elements of Gothic architecture: the use of structure to create space and an abundance of natural light. Six structural pointed arches rise 38 feet atop white-concrete plinths and span the 65-foot-wide nave. Two additional pointed arches cap the ends of the nave at the altar and sanctuary entrance. “When you’re in the sanctuary … you’re surrounded by these arches, [leading back to the idea] that structure makes space,” says lead designer Brian Melton. The arches embed approximately 2 feet deep into 6-foot-tall plinths, where 1/4-inch-thick knife blades connect them to W30-by-184 steel columns that extend down to the building’s footings.
As symbols of radiating energy, 14 to 16 angled glulam struts on each of the six main arches act like flying buttresses to transfer the building’s dead loads: the roof over the 7,000-square-foot sanctuary, the soaring clerestories, and the church’s lower roof. As many as three struts and three knife blades converge at points along the arches.
DiLoreto worked with Portland-based WDY Structural + Civil Engineers to position the struts using SAP2000. The process was “extremely difficult,” Melton says, because each strut orients in three dimensions and originates from different points along the arches.
DiLoreto specified glulam made of locally sourced Douglas fir. Tualatin, Ore.–based Western Wood Structures used computer-controlled clamp beds to form 12 36-foot-long half-arches for the six main arches, and four 24-foot-long half-arches for the two end arches. Tractor-trailers hauled the structural components 25 miles from the Western Wood’s workshop to the church site.
Project builder Grant Co., in Mount Angel, Ore., used a small tower crane to lift each half-arch into place, with two separate boom lifts on each side of the apex and two people at the base guiding it into place. The crew connected the half-arches at the apices with 1-inch-diameter bolts by hand; a 1/4-inch-thick steel plate and 1/4-inch-thick steel knife blade complete the joint detail. All eight arches were erected in one day.
“Due to incredible planning and an amazing builder, the arches fell almost perfectly into place each time with minimal coercing,” Melton says.
Construction began in January 2013 and was completed in February 2014. The church acts as a beacon in the community, as was typical in Gothic times, Melton says. “I hope that the space is uplifting and enhances [the parishioners’] spiritual connection to God and to their community for generations.”