Glu-Lam (Glulam)
An engineered wood product made by bonding multiple layers of dimensional lumber with moisture-resistant adhesives to create large structural beams, columns, and arches.
In-Depth Explanation
Glued-laminated timber is manufactured by stacking and gluing kiln-dried lumber laminations, typically 1-1/2 inches thick, under controlled factory conditions. The resulting beams can be produced in virtually any size, shape, and length, including curved forms for arched roofs and bridges. Glulam provides more consistent strength than solid timber because defects are distributed randomly across multiple laminations. Common species combinations include Douglas fir-larch, southern pine, and spruce-pine-fir, with appearance grades from industrial to architectural. Glulam beams are widely used for ridge beams, headers, and commercial structures requiring long clear spans.
Usage Example
The engineer specified a 6-3/4 by 18 inch architectural-grade glulam beam for the great room ridge, stained to show the lamination lines.