Glued laminated timber

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Glued laminated timber, also called glue-laminated beams or Glulam, is a structural timber product composed of several layers of dimensioned lumber glued together. By laminating several smaller pieces of wood, a single large, strong, structural member can be manufactured from smaller timber. These structural members are used as vertical columns or horizontal beams, often in curved, arching shapes.

Individual structural members are often connected with timber rivets. A timber rivet is a high strength fastener which resembles a nail but has a flattened oval shank with a wedge shaped head. The rivet is driven through pre-drilled holes in a steel side plate until the tapered head is wedged into the hole. Timber rivets have numerous advantages over other fasteners such as bolts and shear plates. They permit a greater load transfer per unit contact area than any other fastener, resulting in substantial saving in the size of steel side plates.

Glulams, like other engineered wood products, represent an efficient use of available timber. With an increased demand for lumber worldwide, the amount of solid timber available has steadily declined. Glulam structural members thus make use of smaller and less desirable dimensions of timber, yet are engineered to be stronger than similarly sized members comprised of solid wood.