Glue-laminated timber, abbreviated to glulam, is the technique of gluing together a slack of relatively thin rectangular-section wood elements to create a larger section element that is typically used as a column or beam.
The great benefit of glue-laminated timber, when compared to a solid wood section of the same size, is that consistency is imparted because any weakness is contained locally to one lath within the buildup. This means greater strength, and also high dimensional stability, because any tendency that wood inevitably has to distort as its moisture content changes is evened out across the element section. Weight-for-weight, glulam is comparable with steel, and performs far better in carbon terms.
Glue-lamination also presents the opportunity of creating curvatures in large timber elements, by individually curving the component planks (which are relatively flexible) during the glue up. This demands special systems of glue-up jigs and clamping. Single curvature (bending in one direction only) is relatively common; we also have expertise in more complex twisting and doubly-curved glue laminated geometries.
Glulam is produced through the carefully controlled gluing of recently-planed timber elements under pressure to ensure maximum strength is achieved - aiming for the glue joint to be stronger than the surrounding wood itself. Longitudinally, continuity of strength is achieved by connecting individual laths end-to-end with glued finger joints. Resin glues are used for durability and high-strength.
Further geometric freedom can be created through multi-axis CNC machining, for example by subtractively machining an oversized glulam section down to a more complex shape. This can prove a cost-effective way of, for example, creating a doubly-curved element from an oversized piece of single-curved glulam.