In October of
2008 the Canadian Lumber Standards Accreditation Board (CLSAB)
accredited PLIB under the new Canadian Treated Wood Program.
Working together CLSAB, the Canadian Standards Association (CSA), the
National Building Code of Canada (NBCC), and industry associations such
as Wood Preservation Canada and the Canadian Wood Council have
developed a national certification program for treated wood to
standardize quality control practices within the industry.
The building code requires that structural wood for residential use be treated in accordance with applicable CSA Standards when:
- Wood is in ground contact, or within 150 mm of ground surface
- Moisture index of >1.00 and wood components are not protected from precipitation
- Wood used in retaining walls and cribbing, critical to structural stability, is >1.2 meters high
- Wood is used in permanent wood foundations
- Wood is within 450 mm of ground surface in areas known to have termites
The national certification program will be based on the CSA 080 Series
Standards for treated wood, published in 2008. A notable change to the
2008 edition is the Use Category (UC) system, for classifying treated
wood based on expected in-service conditions. The four Use Categories specified in the new standard include:
UC1 - Interior Construction, Dry
UC2 - Interior Construction, Damp (not in ground contact)
UC3.2 - Exterior Construction, Above Ground
UC4.1 - Exterior Construction, Ground Contact
UC4.2 - Permanent Wood Foundations, Retaining Walls & Cribbing
Under the national program, treated wood will be marked with reference
to applicable CSA standards and show the endorsement of a CLSAB
accredited agency. PWF material will reference CSA Standard 0322 and
will be marked by stamping only. The use of end tags will not be
permitted with PWF material.
For more information please contact the PLIB office at (253) 835-3344.