These beams are also known as "glulam" beams. They are created by gluing together several layers of different kinds of lumber. The end product is a single strong beam that was created with less energy than steel or concrete. More energy is required to create a glue-laminated beam than a solid timber one, but glue-laminated beams do not require clear-cutting forests and therefore are more environmentally friendly.
Laminated Veneer Beams
These boards are also known as "microlam" beams. They can hold a large amount of weight like their solid beam counterparts but are lighter. Laminated veneer lumber is made from thin sheets of wood that are glued together, much like glue-laminated beams. You will use laminated veneer beams most often for home joists.
Laminated Strand Beams
These beams are created by putting together a number of wood strands with a waterproof adhesive to make a single beam. Laminated strand beams are best for doors and windows because they resist warping and shrinking.