Cross-laminated timber (CLT) is a solid wood board, which is manufactured by glueing boards/battens crosswise in several layers. The dimensions and manufacturing technology of the board varies depending on the manufacturer. Typically, the thickness varies between 51 and 400 mm with the width being no more than 4.8 metres and the length 20 metres.
The most typical uses of CLT are as load-bearing parts for building frames, such as walls, floors and roofs. The boards are also used in facade cladding and interior lining.
They are usually machined into the desired shape in a factory using a CNC (computer numerically controlled) machine. Because of this, it is easy and precise to prepare a board for conversion into a window or door, for example. Usually, the board surface is polished and the material in the surface layers selected so that, if desired, it can be fitted into an interior space unlined.