The light weight of cross-laminated timber (CLT) products combined with the high level of prefabrication involved, in addition to the need to provide wood-based alternative products and systems to steel and concrete, have significantly contributed to the development of CLT products and systems, especially in mid-rise buildings (5 to 9 storeys). While this product is well-established in Europe, work on the implementation of CLT products and systems has just begun in Canada and the USA. The structural efficiency of the floor system acting as a diaphragm and that of walls in resisting lateral loads depends on the efficiency of the fastening systems and connection details used to interconnect individual panels and assemblies. Long self-tapping screws are typically recommended by CLT manufacturers and are commonly used for connecting panels to panels in floors and floorto-wall assemblies. However, there are other types of traditional and innovative fasteners and fastening systems that can be used in CLT assemblies.
This chapter focuses on a few connector systems that reflect present-day practices, some being conventional, others being proprietary. Given the recent introduction of CLT into the construction market, it is expected that new connection types will be developed in time. Issues associated with connection design specific to CLT assemblies are presented. The European design approach is presented and the applicability of CSA O86-09 design provisions for traditional fasteners in CLT such as bolts, dowels, nails and wood screws are reviewed and design guidelines are provided.
The information given in this chapter is aimed at Canadian designers, a group which has expressed a strong interest in specifying CLT products for non-residential and multi-storey applications. However, further studies are needed to assist designers in the development of Canadian engineering design specifications and procedures consistent with Canadian material design standards and the National Building Code of Canada. The technical information will also be used to facilitate code acceptance of CLT products in North America.