Drainage

(1)This Section applies to subsurface drainage and to surface drainage.

(1)Drainage for crawl spaces shall conform to Section 9.18.

(1)Drainage requirements beneath floors-on-ground shall conform to Section 9.16.

(1)Unless it can be shown to be unnecessary, drainage shall be provided at the bottom of every foundation wall that contains the building interior.

(1.1)Except as provided in Sentences (3) and (4), where the insulation on a foundation wall extends to more than 900 mm below the adjacent exterior ground level

• (a) a drainage layer shall be installed adjacent to the exterior surface of a foundation wall consisting of (i) not less than 19 mm mineral fibre insulation with a density of not less than 57 kg/m3, or (ii) not less than 100 mm of free draining granular material, or
• (b) a system shall be installed that can be shown to provide equivalent performance to that provided by the materials described in Clause (a).

(2)Where mineral fibre insulation, crushed rock backfill or other drainage layer medium is provided adjacent to the exterior surface of a foundation wall,

• (a) the insulation, backfill or other drainage layer medium shall extend to the footing level to facilitate drainage of ground water to the foundation drainage system, and
• (b) any pyritic material in the crushed rock shall be limited to a concentration that will not damage the building to a degree that would adversely affect its stability or the performance of assemblies separating dissimilar environments.

(3)Except when the insulation provides the drainage layer required in Clause (2)(a), when exterior insulation is provided, the drainage layer shall be installed on the exterior face of the insulation.

(4)The drainage layer required in Sentence (2) is not required

• (a) when the foundation wall is not required to be dampproofed, or
• (b) when the foundation wall is waterproofed.

(5)Where drainage is required in Sentence (1), the drainage shall conform to Subsection 9.14.3. or 9.14.4.

(1)Drain tile and drain pipe for foundation drainage shall conform to

• (a) ASTM C4, "Standard Specification for Clay Drain Tile and Perforated Clay Drain Tile,"
• (b) ASTM C412M, "Standard Specification for Concrete Drain Tile,"
• (c) ASTM C444M, "Perforated Concrete Pipe,"
• (d) ASTM C700, "Standard Specification for Vitrified Clay Pipe, Extra Strength, Standard Strength and Perforated,"
• (e) BNQ 3624-115, "Polyethylene (PE) Pipe and Fittings for Soil and Foundation Drainage,"
• (f) CAN/CSA-B182.1, "Plastic drain and sewer pipe and pipe fittings," or
• (g) CAN/CSA-G401, "Corrugated steel pipe products."

(1)Drain tile or pipe used for foundation drainage shall be not less than 100 mm in diam.

(1)Drain tile or pipe shall be laid on undisturbed or well-compacted soil so that the top of the tile or pipe is below the bottom of the floor slab or the ground cover of the crawl space.

(2)Drain tile or pipe with butt joints shall be laid with 6 mm to 10 mm open joints.

(3)The top half of joints referred to in Sentence (2) shall be covered with sheathing paper, 0.10 mm polyethylene or No. 15 asphalt or tar-saturated felt.

(4)The top and sides of drain pipe or tile shall be covered with not less than 150 mm of crushed stone or other coarse clean granular material containing not more than 10% of material that will pass a 4 mm sieve.

(1)Granular material used to drain the bottom of a foundation shall consist of a continuous layer of crushed stone or other coarse clean granular material containing

• (a) not more than 10% of material that will pass a 4 mm sieve, and
• (b) no pyritic material in a concentration that would adversely affect its stability or the performance of assemblies separating dissimilar environments.

(1)Granular material described in Article 9.14.4.1. shall be laid on undisturbed or compacted soil to a minimum depth of not less than 125 mm beneath the footing of the building and extend not less than 300 mm beyond the outside edge of the footings.

(1)The bottom of an excavation drained by a granular layer shall be graded so that the entire area described in Article 9.14.4.2. is drained to a sump conforming to Article 9.14.5.2.

(1)Where because of wet site conditions soil becomes mixed with the granular drainage material, sufficient additional granular material shall be provided so that the top 125 mm are kept free of soil.

(1)Foundation drains shall drain to a sewer, drainage ditch or dry well.

(1)Where a sump pit is provided it shall be

• (a) not less than 750 mm deep,
• (b) not less than 0.25 m2 in area, and
• (c) provided with a cover.

(2)Covers for sump pits shall be designed

• (a) to resist removal by children, and
• (b) to be airtight in accordance with Sentence 9.25.3.3.(7)

(3)Where gravity drainage is not practical, an automatic sump pump shall be provided to discharge the water from the sump pit described in Sentence (1) into a sewer, drainage ditch or dry well.

(1)Dry wells may be used only when located in areas where the natural groundwater level is below the bottom of the dry well.

(2)Dry wells shall be not less than 5 m from the building foundation and located so that drainage is away from the building.

(1)The building shall be located or the building site graded so that water will not accumulate at or near the building and will not adversely affect adjacent properties.

(1)Surface drainage shall be directed away from the location of a water supply well or leaching bed.

(1)Every window well shall be drained to the footing level or other suitable location.

(1)Where runoff water from a driveway is likely to accumulate or enter a garage, a catch basin shall be installed to provide adequate drainage.

(1)Downspouts shall conform to Article 9.26.18.2.