What is the difference between balanced and unbalanced glulam?
Glulam allows the manufacturer to place wood species in the lay-up to the material’s best advantage in resisting applied stresses. The whole premise of a glued laminated beam is that you are trying to put the high strength material in the extreme zones of the cross sectional member, so when the beam is loaded, the high strength material is located where the stresses would be the highest. In an unbalanced beam lay-up, the grade and stress values for the lams on the compression side are not as high as the stress rating for the tension lams. Since wood is weaker in tension, higher strength material is placed on the tension lams than in the compression lams. This particular beam would definitely have a top and a bottom to it, and is popular in simple span applications. Thus, “Glulam Unbalanced” is used where the top is in compression. In a balanced beam lay-up, the laminations that are used on the extreme ends of the section on either side are the same grade and stress rating. This means t
