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Treated Wood Program PDF Print E-mail
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.