When timber is required in greater lengths and cross-sections than can be obtained economically from available logs, larger sizes have to be fabricated by gluing together smaller pieces of timber with their grain directions parallel to each other - a process known as laminating. Laminating permits the manufacture of curved members and allows strength-reducing defects such as knots to be dispersed throughout the cross-section of them, thus in effect upgrading poor quality material. A further advantage is that a member to be used in an indoor environment can be made from laminations which have been kiln-dried before gluing and therefore may be designed using the higher working stresses appropriate to the lower moisture content.

Originally published June 1966; revised August 1968 and April 1971, reprinted 1974.