How to Protect Glulam From Moisture and Pests

Glulam (glued laminated timber) is an engineered wood product made of laminations of stress-graded, seasoned and kiln-dried lumber which are then secured together using strong yet long-term adhesives.

Glulam structures combine strength with design flexibility, from wedding chapel ceilings to purlins, ridge beams and garage door headers. Furthermore, its superior fire protection makes Glulam an eco-friendly building material.

Moisture

As with any wood product, glulam will experience changes in moisture content throughout its hygroscopic lifecycle, leading to expansion and contraction of its elements – something which when coupled with other factors may result in seasoning checks on boards’ ends. Though these seasoning checks don’t degrade the quality or performance of a glulam, they do add undesirable aesthetic features which should be limited as much as possible. Controlling handling and storage practices at distribution yards and jobsite storage, scheduling construction to minimize jobsite storage requirements, and protecting glulam members against climate influences such as rainfall or high temperatures are ways of accomplishing this goal.

Glulam elements are usually shipped with protective stretch wrap to guard against damage during transit, however this does not provide long-term storage protection from weather influences.

Water Damage

Moisture exposure can expose glulam to damage during transportation, storage and construction processes. Therefore it is crucial that effective handling practices be employed during loading, unloading and transit of long beams to minimize risks. Stacking timbers on lumber blockings, skids or rack systems to reduce flexing is helpful while spreader bars reduce corner and edge damages; fabric slings are recommended over metal ones to decrease chances of accidental damage to corners and edges.

Long-term storage requires using a cover to protect glulam from weather influences and moisture fluctuations, and level supports or bed timber should be used to avoid imprinting. In accordance with all wood products, shrink fissures may appear due to exposure to humidity changes; these are normal and do not constitute grounds for complaint; but must be treated carefully to prevent water leakage and damage.