The Ontario Building Code | Preservation Treatment of Wood

4.2.3.2. Preservation Treatment of wood

(1) wood exposed to soil or air above the lowest anticipated groundwater table shall be treated with preservative in conformance with CAN/CSA-O80 Series, "wood Preservation", and the requirements of the appropriate commodity standard as follows:

(a) CAN/CSA-O80.2, "Processing and Treatment",

(b) CAN/CSA-O80.3, "Preservative Formulations", or

(c) CSA O80.15, "Preservative Treatment of wood for building Foundation Systems, basements and Crawl Spaces by pressure Processes".