Carcassing - CLS timbers

Southern Timber CLS timbers are imported only from the Baltic, or Scandinavia, and all stock is regularised, kiln dried and graded at the sawmills to BS4978 strength classes C16 and C24. However, 2.4 metre lengths are untreated and only the 4.8 metre lengths are pressure treated to a minimum Hazard Class 3 to minimise any deterioration from damp in building installations and external exposure.

CLS carcassing timbers have a planed finish with eased edges and are normally used in studwork partition walls. The finish sizes are quite different from the nominal sizes, typical sizes are 47mm x 75mm (40mm x 65mm); 47mm x 100mm (40mm x 90mm) and 47mm x 150mm (40mm x 140mm).