By laminating a number of smaller pieces of timber, a single large, strong, structural member is manufactured from smaller pieces. These structural members are used as vertical columns or horizontal beams, as well as curved, arched shapes. Glulam is readily produced in curved shapes and it is available in a range of species and appearance characteristics to meet varied end-use requirements. Connections are usually made with bolts or plain steel dowels and steel plates.

G lued laminated timber, also called Glulam, is a type of structural timber product comprising a number of layers of dimensioned timber bonded together with durable, moisture-resistant structural adhesives. In North America the material providing the laminations is termed laminating stock or lamstock.

Sports structures are a particularly suitable application for wide-span glulam roofs. This is supported by the light weight of the material, combined with the ability to furnish long lengths and large cross-sections. Prefabrication is invariably employed and the structural engineer needs to develop clear methods statements for delivery and erection at an early stage in the design. The PostFinance Arena is an example of a wide-span sports stadium roof using glulam arches reaching up to 85 metres. The structure was built in Berne in 1967, and has subsequently been refurbished and extended.

The roof of the Richmond Olympic Oval, built for speed skating events at the 2010 Winter Olympic Games in Vancouver, British Columbia, features one of the world's largest clearspan wooden structures. The roof includes 2,400 cubic metres of Douglas-fir lamstock lumber in glulam beams. A total of 34 yellow-cedar glulam posts support the overhangs where the roof extends beyond the walls.


 Glulam has much lower embodied energy than reinforced concrete and steel, although of course it does entail more embodied energy than solid timber. However, the laminating process allows timber to be used for much longer spans, heavier loads, and complex shapes. Glulam is two-thirds the weight of steel and one sixth the weight of concrete – the embodied energy to produce it is six times less than the same suitable strength of steel.

-Glulam can be manufactured to a variety of straight and curved configurations so it offers architects artistic freedom without sacrificing structural requirements.

-Wood has a greater tensile strength relative to steel – two times on a strength-to-weight basis – and has a greater compressive resistance strength than concrete. The high strength and stiffness of laminated timbers enable glulam beams and arches to span large distances without intermediate columns, allowing more design flexibility than with traditional timber construction. The size is limited only by transportation and handling constraints.


 

A 2002 case study comparing energy use, greenhouse gas emissions and costs for roof beams found it takes two to three times more energy and six to twelve times more fossil fuels to manufacture steel beams than it does to manufacture glulam beams. It compared two options for a roof structure of a new airport in Oslo, Norway – steel beams and glulam spruce wood beams. The life cycle greenhouse gas emission is lower for the glulam beams. If they are burned at the end of their service life, more energy can be recovered than was used to manufacture them. If they are landfilled, the glulam beams result in greater greenhouse gas emissions than the steel beams. The cost of the glulam beams is slightly lower than the steel beams

Glulam optimizes the structural values of a renewable resource – wood. Because of their composition, large glulam members can be manufactured from a variety of smaller trees harvested from second- and third-growth forests and plantations. Glulam provides the strength and versatility of large wood members without relying on the old growth-dependent solid-sawn timbers.  It reduces the overall amount of wood used when compared to solid sawn timbers by diminishing the negative impact of knots and other small defects in each component board.