Dramatic strength combined with zero shrinkage puts engineered beams and headers on more and more job sites.
Synopsis: A general discussion of laminated strand lumber (LSL), glue laminated timber (glulam), laminated veneer lumber (LVL), and parallel strand lumber (Parallam), including a brief background of each material, a comparison of the costs, strength, appearance, and availability of each, and a description of how each is best utilized on the job site.
Engineered structural beams made their North American debut in 1934 in Peshtigo, Wisconsin, just north of Green Bay. Glue laminated timber (or glulam) had been widely used in Europe for decades, but when Max Hanisch, a German immigrant, suggested glulam for the new gymnasium at Peshtigo High School, building traditionalists balked. The Wisconsin State Industrial Commission demanded steel reinforcements, but Hanisch prevailed. He and his partners supplied arched glulam beams that are still in service nearly 70 years later.
That was then. Now manufacturers combine relatively small pieces of wood with adhesives to form a variety of structural members…