Section 9.3. Materials, Systems and Equipment

9.3.1. Concrete

9.3.1.1. General

(1) Except as provided in Sentence (2), nominally unreinforced concrete shall be designed, mixed, placed, cured and tested in accordance with CAN/CSA-A438, "Concrete Construction for Housing and Small Buildings".
(2) Nominally unreinforced site-batched concrete shall be designed, mixed, placed and cured in accordance with Articles 9.3.1.2. to 9.3.1.9.
(3) Except as provided in Sentence (4), Subsection 9.15.4. and Section 9.40., reinforced concrete shall be designed to conform to the requirements of Part 4.
(4) For flat insulating concrete form walls not exceeding 2 storeys in building height, and having a maximum floor to floor height of 3 m (9 ft 10 in), in buildings of light frame construction containing only a single dwelling unit, the concrete and reinforcing shall comply with Part 4 or,

(a) concrete shall conform to CAN/CSA-A23.1, "Concrete Materials and Methods of Concrete Construction", with a maximum aggregate size of 19 mm (3/4 in), and
(b) reinforcing shall,
(i) conform to CAN/CSA-G30.18-M, "Billet Steel Bars for Concrete Reinforcement",
(ii) have a minimum specified yield strength of 400 MPa (58,000 psi), and
(iii) be lapped a minimum of 450 mm (17-3/4 in) for 10M bars and 650 mm (2 ft 1-1/2 in) for 15M bars.

9.3.1.2. Cement

(1) Cement shall meet the requirements of CAN/CSA-A3001, "Cementitious Materials for Use in Concrete".

9.3.1.3. Concrete in Contact with Sulfate Soil

(1) Concrete in contact with sulfate soil, which is deleterious to normal cement, shall conform to the requirements in Clause 4.1.1.6. of CAN/CSA-A23.1, "Concrete Materials and Methods of Concrete Construction".

9.3.1.4. Aggregates

(1) Aggregates shall,
(a) consist of sand, gravel, crushed rock, crushed air-cooled blast furnace slag, expanded shale or expanded clay conforming to CAN/CSA-A23.1, "Concrete Materials and Methods of Concrete Construction", and
(b) be clean, well-graded and free of injurious amounts of organic and other deleterious material.

9.3.1.5. Water

(1) Water shall be clean and free of injurious amounts of oil, organic matter, sediment or any other deleterious material.

9.3.1.6. Compressive Strength

(1) Except as provided elsewhere in this Part, the compressive strength of unreinforced concrete after 28 days shall be not less than,
(a) 32 MPa (4650 psi) for garage floors, carport floors and all exterior flat work,
(b) 20 MPa (2900 psi) for interior floors other than those for garages and carports, and
(c) 15 MPa (2200 psi) for all other applications.
(2) Concrete used for garage and carport floors and exterior steps shall have air entrainment of 5 to 8%.

9.3.1.7. Concrete Mixes

te(1) For site-batched concrete, the concrete mixes described in Table 9.3.1.7. shall be considered acceptable if the ratio of water to cementing materials does not exceed,
(a) 0.45 for garage floors, carport floors and all exterior flat work,
(b) 0.65 for interior floors other than those for garages and carports, and
(c) 0.70 for all other applications.xt

Table 9.3.1.7.
Concrete Mixes
Forming Part of Sentence 9.3.17.(1)

(2) The size of aggregate in unreinforced concrete mixes referred to in Sentence (1) shall not exceed,
(a) 1/5 the distance between the sides of vertical forms, or
(b) 1/3 the thickness of flat work.

9.3.1.8. Admixtures

(1) Admixtures shall conform to ASTM C260, "Air-Entraining Admixtures for Concrete", or ASTM C494 / C494M, "Chemical Admixtures for Concrete", as applicable.

9.3.1.9. Cold Weather Requirements

(1) When the air temperature is below 5°C (41 °F), concrete shall be,
(a) kept at a temperature of not less than 10°C (50°F) or more than 25°C (77°F) while being placed, and
(b) maintained at a temperature of not less than 10°C (50°F) for 72 h after placing.
(2) No frozen material or ice shall be used in concrete described in Sentence (1).

9.3.2. Lumber and Wood Products

9.3.2.1. Grade Marking

(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 the NLGA, "Standard Grading Rules for Canadian Lumber". (See Appendix A.)

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

9.3.2.2. Lumber Grades

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

9.3.2.3. Machine Stress Rated Lumber

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

9.3.2.4. OSB, Wafer-board and Plywood Marking

(1) OSB, wafer-board and plywood used for roof sheathing, wall sheathing and sub-flooring shall be legibly identified on the face of the material indicating,
(a) the manufacturer of the material,
(b) the standard to which it is produced, and
(c) that the material is of an exterior type.

9.3.2.6. Lumber Dimensions

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

9.3.2.7. Panel Thickness Tolerances

(1) The thickness 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 in this Part.

9.3.2.8. Undersized Lumber

(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 Appendix A.)

9.3.2.9. Termite and Decay Protection

(1) In localities where termites are known to occur,
(a) clearance between structural wood elements and the finished ground level directly below them shall be not less than 450 mm (1734 in) and, except as provided in Sentence (2), all sides of the supporting elements shall be visible to permit inspection, or
(b) 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.

(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,
(a) 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
(b) all sides of the finish supporting assembly shall be visible to permit inspection.

(3) Structural wood elements shall be pressure-treated with a preservative to resist decay where the vertical clearance between structural wood elements and the finished ground level is less than 150 mm (57/a in). (See Appendix A.)

(4) Structural wood elements used in retaining walls and cribbing shall be pressure-treated with a preservative to resist decay, where,
(a) the retaining wall or cribbing supports ground that is critical to the stability of building foundations, or
(b) the retaining wall or cribbing is greater than 1.2 m (3 ft 11 in) in height. (See Appendix A.)

(5) Where wood is required by this Article to be treated to resist termites or decay, such treatment shall be in accordance with the requirements of,
(a) CSA O80.1, "Preservative Treatment of All Timber Products by Pressure Processes",
(b) CSA O80.2, "Preservative Treatment of Lumber, Timber, Bridge Ties and Mine Ties by Pressure Processes",
(c) CSA O80.9, "Preservative Treatment of Plywood by Pressure Processes",
(d) CSA O80.15, "Preservative Treatment of Wood for Building Foundation Systems, Basements and Crawl Spaces by Pressure Processes",
(e) CSA O80.34, "Pressure Preservative Treatment of Lumber and Timbers with Borates for Use Out of Ground Contact and Continuously Protected from Liquid Water", or
(f) CSA O80.36, "Preservative Treatment of Wood Products for Light-Duty Above-Ground Residential Uses by Pressure Processes".

(6) In addition to the requirements of Clause (5)(e), where wood is protected in accordance with CSA O80.34, "Pressure Preservative Treatment of Lumber and Timbers with Borates for Use Out of Ground Contact and Continuously Protected from Liquid Water", the wood shall be,
(a) protected from direct exposure to moisture during and after the completion of construction, and
(b) separated from permeable supporting materials by a moisture barrier that is resistant to all expected mechanisms of deterioration in the service environment when the vertical clearance to the ground is less than 150 mm (5% in).

(7) Wood that is required by this Article to be treated to resist termites or decay shall be identified by a mark to indicate its conformance to the relevant required standard.

9.3.3. Metal

9.3.3.1. Sheet Metal Thickness

(1) Minimum thicknesses for sheet metal material required in this Part refer to the actual minimum base metal thicknesses measured at any point of the material, and in the case of galvanized steel described in Sentence 9.3.3.2.(1), include the thickness of the galvanizing coating unless otherwise indicated.

9.3.3.2. Galvanized Sheet Steel

(1) Where sheet steel is required to be galvanized, it shall be metallic-coated with zinc or an alloy of 55% aluminium-zinc meeting the requirements of ,
(a) ASTM A653 / A653M, "Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvanealed) by the Hot-Dip Process", or
(b) ASTM A792 / A792M, "Sheet Steel, 55% Aluminium-Zinc Alloy-Coated by the Hot Dip Process".

(2) Where galvanized sheet steel is intended for use in locations exposed to the weather or as a flashing material, it shall have a zinc coating not less than the G90 (Z275) coating designation or an aluminum-zinc alloy coating not less than the AZM150 coating designation, as referred to in Sentence (I).