Canadian Lumber Standard, typically abbrievated as CLS, is a type and standard/grade of processed and sawn

lumber Lumber is wood that has been processed into uniform and useful sizes (dimensional lumber), including beams and planks or boards. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, window frames). ...

(timber) used in many countries.

History

CLS was originally a product of Canada used in the construction of sturdy timber-framed houses as rated by the Canadian Lumber Standards Accreditation Board (CLSAB). Following the end of the

Cold War The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...

it was increasingly used by manufacturers in Baltic countries as a reference grade for export to the UK and other Western European countries. For these reasons, Latvian CLS, Swedish CLS and other European graded timber are now available, despite not originating from Canada. Most CLS now originates from Europe, including

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

Usage

CLS is primarily used in internal construction because of is strength and durability. As such, CLS is widely utilised as a general standard for timber suitable for wall studs, DIY and other

construction Construction are processes involved in delivering buildings, infrastructure, industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design that continues until the a ...

projects, including housebuilding. It is very commonly employed in conventional timber frames for roofs, lofts and attics. It is typically used in the UK for timber wall studs. For use outside, CLS timber should be treated for external use.

Details

CLS timber is kiln-dried and is white wood. Tree sources include

Fir Firs are evergreen coniferous trees belonging to the genus ''Abies'' () in the family Pinaceae. There are approximately 48–65 extant species, found on mountains throughout much of North and Central America, Eurasia, and North Africa. The genu ...

Pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. ''World Flora Online'' accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as cu ...

and

Spruce A spruce is a tree of the genus ''Picea'' ( ), a genus of about 40 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal ecosystem, boreal (taiga) regions of the Northern hemisphere. ''Picea'' ...

. CLS is planed and fished with eased or rounded edges. CLS timber is commonly graded at two strengths, C16 or C24. C24 is the stronger and is typically more expensive. It is often pressure treated and may also be treated with pesticides to stop insect and fungal growth.

References

{{Wood products Forestry Timber industry Wood products Woodworking