Although some historic downtown churches are closing, new church construction is increasing across the United States. Exposed glued laminated trusses and beams are an increasingly popular choice for many of the new structures because they provide extra strength for long spans and dramatic interiors at a competitive cost. According to the American Institute of Timber Construction (AITC), about 30 percent of all glulam beams and trusses manufactured in the United States are used in commercial and institutional construction, a sizeable increase over the past five years.
Glulam timbers and arches are also a renewable resource because U.S. foresters plant 45 million trees daily to ensure a future supply of wood. Glued laminated timbers are a stress-rated engineered wood product comprised of wood laminations, or "lams," bonded together with strong, waterproof adhesive. This means that no large, old-growth trees are needed in the fabrication of the beams.
The recently completed Most Blessed Sacrament Catholic Church in Baton Rouge, Louisiana, showcases glulam timber in its 950-seat, 16,831-square-foot church and 7,920-square-foot administration center. The existing rectory was converted to school functions.
Post Architects, the designers, note that the glulam trusses help to avoid a feeling of separation between the higher nave axis and the lower roof areas. Another highlight of the interior is a wood window wall which is built around an exposed glulam truss and separates the Nave from the Narthex.
In order to provide a long nave with stained glass clerestory windows, exposed glulam scissor trussses were specified, 20 feet on center. A hidden ladder steel truss helps to provide a clear span "column-less" seating area. The steel structure supports the trusses and is imbedded in the clerestory wall. Glulam girders span the scissors trusses and support the exposed glulam roof deck which reduced construction costs because it functions as an interior ceiling and structural roof.
The structural engineer, Dean McKee of McKee and Deville, notes that a unique aspect of the erection was using special caution in bolting the glulam trusses to the steel ladder truss to avoid lateral deflection and keep both trusses level.
Steel and concrete columns are 60 feet high. The glulam trusses span 48 feet. Top and bottom chords are 8-5/8 feet by 24 feet 5 inches. The glulam was specified to create a warm character and expose the structure to create a aesthetic feel, rather than more expensive materials such as stone.
Timber-framed interiors are also gaining in popularity because when glulam materials arrive at the job site prefinished, this delivered product is the finished product. Other types of framing members arrive on-site in raw form, and require additional cladding to create the final component.
Jake Mayo of Buquet & Leblanc, Inc., the contractor, says, "The prefinished glulam trusses and beams give the building an authentic feel that is often missed with concrete and steel structures. From a contractor's view, it is nice to get a finished product installed early in the schedule. Once the beams and decking were finished, the only thing left for us to complete for the ceiling was the light fixtures."