Glued Laminated Timber (Glulam) is one of the three main engineering timber products together with wooden I-beams and veneer laminates. It is a small-sized solid wood sawn timber, which is a kind of engineering wood made of cold-curing adhesive and bonded along the grain direction.
Physical and mechanical properties
Compared with finished wood, plywood (integrated wood) has higher strength, allowable bending stress can be increased by 50%, and the structure is uniform, the internal stress is small, and it is not easy to crack and warp deformation; the integrated wood with large cross-section also has higher fire resistance . In addition, the laminated wood does not have the problem of veneer cracks, so it is more suitable for building beams than LVL.
Durability is an important indicator to measure the quality of glulam (plywood), which directly affects its service life. The Japanese integrated timber standard stipulates that the stripping rate of the test piece is less than 10%, and the stripping length of the same glue seam is less than 1/3 of the glue seam length is qualified. Experiments have shown that phenolic glue glue has the best durability, followed by melamine resin glue, and urea resin glue is the worst. 
Advantages of glulam (integrated wood) for structural use:
(1) Because of the use of dry materials, it can prevent deformation and cracking during use;
(2) The dimensional freedom is large, and it can meet the beam requirements of span and cross-sectional shape;
(3) Give full play to the characteristics of wood, absorb vibration and decorate randomly;
(4) It is easy to carry out antiseptic and insect repellent treatment, and the effect is good.