1. Lumber for joists, rafters, trusses and beams and for the uses listed in Table 9.3.2.1. shall be identified by a grade stamp to indicate its grade as determined by NLGA 2014, "Standard Grading Rules for Canadian Lumber."
   (See Note A-9.3.2.1.(1).)

Table 9.3.2.1.
Minimum Lumber Grades for Specific End Uses
Forming Part of Sentence 9.3.2.1.(1)

Notes to Table 9.3.2.1.:

(1) See Note A-Table 9.3.2.1.

1. Except for joists, rafters, trusses and beams, visually graded lumber shall conform to the grades in Table 9.3.2.1. (See Article 9.23.4.2. for joists, rafters and beams and Article 9.23.14.11. for trusses.)

1. Machine stress rated lumber shall conform to the requirements of Subsection 4.3.1.

1. OSB, waferboard and plywood used for roof sheathing, wall sheathing and subflooring shall be legibly identified on the face of the material indicating
   1. the manufacturer of the material,
   2. the standard to which it is produced, and
   3. that the material is of an exterior type.

1. Moisture content of lumber shall be not more than 19% at the time of installation.

1. Lumber dimensions referred to in this Part are actual dimensions determined in conformance with CSA O141, "Softwood Lumber."

1. The thicknesses specified in this Part for plywood, hardboard, particleboard, OSB and waferboard shall be subject to the tolerances permitted in the standards referenced for these products unless specifically indicated herein.

1. Joist, rafter, lintel and beam members up to 5% less than the actual Canadian standard sizes are permitted to be used provided the allowable spans for the grade and species of lumber under consideration are reduced 5% from those shown in the Span Tables for full size members.
   (See Note A-9.3.2.8.(1).)

1. In localities where termites are known to occur,
   1. clearance between structural wood elements and the finished ground level directly below them shall be not less than 450 mm and, except as provided in Sentence (2), all sides of the supporting elements shall be visible to permit inspection, or
   2. structural wood elements, supported by elements in contact with the ground or exposed over bare soil, shall be pressure-treated with a chemical that is toxic to termites. (See Note A-9.3.2.9.(1).)
2. In localities where termites are known to occur and foundations are insulated or otherwise finished in a manner that could conceal a termite infestation,
   1. a metal or plastic barrier shall be installed through the insulation and any other separation or finish materials above finished ground level to control the passage of termites behind or through the insulation, separation or finish materials, and
   2. all sides of the finished supporting assembly shall be visible to permit inspection.
3. Structural wood elements shall be pressure-treated with a preservative to resist decay,
   1. where the vertical clearance between structural wood elements and the finished ground level is less than 150 mm (see also Articles 9.23.2.2. and 9.23.2.3.), or
   2. where
      1. the wood elements are not protected from exposure to precipitation,
      2. the configuration is conducive to moisture accumulation, and
      3. the moisture index is greater than 1.00. (See Note A-9.3.2.9.(3).)
4. Structural wood elements used in retaining walls and cribbing shall be pressure-treated with a preservative to resist decay, where
   1. the retaining wall or cribbing supports ground that is critical to the stability of building foundations, or
   2. the retaining wall or cribbing is greater than 1.2 m in height. (See Note A-9.3.2.9.(4).)
5. Where wood is required by this Article to be treated to resist termites or decay, such treatment shall be in accordance with Table 2, Use Categories for Specific Products, Uses, and Exposures, of CAN/CSA-O80.1, "Specification of Treated Wood," as follows:
   1. Use Category 1 (UC1), where the wood member is used in
      1. interior construction,
      2. above-ground applications, and
      3. applications where the wood member remains dry,
   2. Use Category 2 (UC2), where the wood member is used in
      1. interior construction,
      2. above-ground applications, and
      3. applications where the wood member may be subjected to occasional sources of moisture,
   3. Use Category 3.2 (UC3.2), where the wood member is used in
      1. exterior construction,
      2. above-ground applications, and
      3. applications where the wood member is uncoated or is used in a configuration conducive to moisture accumulation,
   4. Use Category 4.1 (UC4.1), where
      1. the wood member is in contact with the ground,
      2. the wood member is in contact with fresh water, or
      3. the vertical clearance between the wood element and the finished ground level is less than 150 mm and the wood elements are not separated from permeable supporting materials by a moisture barrier, or
   5. Use Category 4.2 (UC4.2), where the wood member is used in critical structural components, including permanent wood foundations.
6. Where wood is protected in accordance with UC1 or UC2 using an inorganic boron preservative, the wood shall be
   1. protected from direct exposure to water during and after the completion of construction, and
   2. separated from permeable supporting materials by a moisture barrier that is resistant to all expected mechanisms of deterioration in the service environment if the vertical clearance to the ground is less than 150 mm.
7. Wood that is required by this Article to be treated to resist termites or decay shall be identified by a mark to indicate the type of preservative used and conformance to the relevant required Use Category.