CodeChronicle

OBC 2006 Division B

9.15.

Version 0 — in force 31 December 2006

In force
Verified · covered Verified against the 2006-12-31–2007-04-01 consolidation, whose range covers the query date. How to read this

Provenance

OBC 1997 · continues from 9.15. — Pro

Base · O. Reg. 350/06 · ext← current

Original — base regulation

OBC 2012 · continues as 9.15. — Pro

9.15. — Footings and Foundations

Content not available for this version.

9.15.1. — Application

Content not available for this version.

9.15.1.1. — General

(1) Except as provided in Articles 9.15.1.2. and 9.15.1.3., this Section applies to,

(a) concrete or unit masonry foundation walls and concrete footings not subject to surcharge,

(i) on stable soils with an allowable bearing pressure of 75 kPa or greater, and

(ii) for buildings of wood frame or masonry construction,

(b) wood frame foundation walls and wood or concrete footings not subject to surcharge,

(i) on stable soils with an allowable bearing pressure of 75 kPa or greater, and

(ii) for buildings of wood frame construction, and

(c) flat insulating concrete form foundation walls and concrete footings not subject to surcharge,

(i) on stable soils with an allowable bearing pressure of 100 kPa or greater, and

(ii) for buildings of light frame or flat insulated concrete form construction that are not more than 2 storeys in building height, with a maximum floor to floor height of 3 m, and containing only a single dwelling unit.

(2) Foundations for applications other than as described in Sentence (1) shall be designed in accordance with Section 9.4.

(3) Where a foundation is erected on filled ground, peat or sensitive clay, the footing sizes shall be designed in conformance with Section 4.2.

(4) For the purpose of Sentence (3), sensitive clay means the grain size of the majority of the particles is smaller than 0.002 mm, including leda clay.

Text · e-Laws consolidated snapshot

9.15.1.2. — Permafrost

(1) Buildings erected on permafrost shall have foundations designed by a designer competent in this field in accordance with the appropriate requirements of Part 4.

Text · e-Laws consolidated snapshot

9.15.1.3. — Foundations for Deformation Resistant Buildings

(1) Where the superstructure of a detached building conforms to the requirements of the deformation resistance test in CAN/CSA-Z240.2.1, “Structural Requirements for Mobile Homes”, the foundation shall be constructed in conformance with,

(a) the remainder of this Section, or

(b) CSA Z240.10.1, “Site Preparation, Foundation, and Anchorage of Mobile Homes”.

Text · e-Laws consolidated snapshot

9.15.2. — General

Content not available for this version.

9.15.2.1. — Concrete

(1) Concrete shall conform to Section 9.3.

Text · e-Laws consolidated snapshot

9.15.2.2. — Unit Masonry Construction

(1) Concrete block shall conform to CSA A165.1, “Concrete Block Masonry Units”, and shall have a compressive strength over the average net cross-sectional area of the block of not less than 15 MPa.

(2) Mortar, grout, mortar joints, corbelling and protection for unit masonry shall conform to Section 9.20.

(3) For concrete block foundation walls required to be reinforced,

(a) mortar shall be Type S, conforming to CSA A179, “Mortar and Grout for Unit Masonry”,

(b) grout shall be coarse, conforming to CSA A179, “Mortar and Grout for Unit Masonry”, and

(c) placement of grout shall conform to CSA A371, “Masonry Construction for Buildings”.

Text · e-Laws consolidated snapshot

9.15.2.3. — Pier Type Foundations

(1) Where pier type foundations are used, the piers shall be designed to support the applied loads from the superstructure.

(2) Where piers are used as a foundation system in a building of 1 storey in building height, the piers shall be installed to support the principal framing members and shall be spaced not more than 3.5 m apart along the framing, unless the piers and their footings are designed for larger spacings.

(3) The height of piers described in Sentence (2) shall not exceed 3 times their least dimension at the base of the pier.

(4) Where concrete block is used for piers described in Sentence (2), they shall be laid with cores placed vertically, and where the width of the building is 4.3 m or less, placed with their longest dimension at right angles to the longest dimension of the building.

Text · e-Laws consolidated snapshot

9.15.2.4. — Wood Frame Foundations

(1) Foundations of wood frame construction shall conform to,

(a) CAN/CSA-S406, “Construction of Preserved Wood Foundations”, or

(b) Part 4.

Text · e-Laws consolidated snapshot

9.15.3. — Footings

Content not available for this version.

9.15.3.1. — Footings Required

(1) Footings shall be provided under walls, pilasters, columns, piers, fireplaces and chimneys that bear on soil or rock, except that footings are permitted to be omitted under piers or monolithic concrete walls if the safe loadbearing capacity of the soil or rock is not exceeded.

Text · e-Laws consolidated snapshot

9.15.3.2. — Support of Footings

(1) Footings shall rest on undisturbed soil, rock or compacted granular fill.

(2) Granular fill shall not contain pyritic material in a concentration that would adversely affect its stability or the performance of assemblies separating dissimilar environments.

Text · e-Laws consolidated snapshot

9.15.3.3. — Application of Footing Width and Area Requirements

(1) Except as provided in Sentence 9.15.3.4.(2), the minimum footing width or area requirements provided in Articles 9.15.3.4. to 9.15.3.7. shall apply to footings where,

(a) the footings support,

(i) foundation walls of masonry, concrete, or flat insulating form foundation walls,

(ii) above ground walls of masonry, flat insulating form foundation walls or light wood frame construction, and

(iii) floors and roofs of light wood frame construction,

(b) the span of supported joists does not exceed 4.9 m, and

(c) the specified live load on any floor supported by the footing does not exceed 2.4 kPa.

(2) Except as provided in Sentence 9.15.3.4.(2), where the span of the supported joists exceeds 4.9 m, footings shall be designed in accordance with Section 4.2.

(3) Where the specified live load exceeds 2.4 kPa footings shall be designed in accordance with Section 4.2.

Text · e-Laws consolidated snapshot

9.15.3.4. — Basic Footing Widths and Areas

(1) Except as provided in Sentences (2) and (3) and in Articles 9.15.3.5. to 9.15.3.7., the minimum footing width or area shall comply with Table 9.15.3.4.

(2) Where the supported joist span exceeds 4.9 m in buildings with light wood-framed walls, floors and roofs, footing widths shall be determined according to,

(a) Section 4.2., or

(b) the following formula:

W = w • [∑ sjs / (storeys • 4.9)]

where,

W = minimum footing width,

w = minimum width of footings supporting joists not exceeding 4.9 m, as defined by Table 9.15.3.4.,

∑ sjs = the sum of the supported joist lengths on each storey whose load is transferred to the footing, and

storeys = number of storeys supported by the footing

(3) Where a foundation rests on gravel, sand or silt in which the water table level is less than the width of the footings below the bearing surface,

(a) the footing width for walls shall be not less than twice the width required by Sentences (1) and (2), and Articles 9.15.3.5. and 9.15.3.6., and

(b) the footing area for columns shall be not less than twice the area required by Sentences (1) and (2), and Article 9.15.3.7.

Editor's note

In the notes to Table-9.15.3.4., the footnote reference numbers are presented inline with a separating space; the e-Laws consolidation renders them as superscript abutting the text. The footnote text is identical.

Text · e-Laws consolidated snapshot

Table 9.15.3.4. Minimum Footing Sizes Forming Part of Sentence 9.15.3.4.(1)

Column 1

Column 2

Column 3

Column 4

Number of Floors Supported

Minimum Width of Strip Footings, mm

Minimum Footing Area for Columns Spaced 3 m o.c.(1), m2

Supporting Exterior Walls(2)

Supporting Interior Walls(3)

1

250

200

0.40

2

350

350

0.75

3

450

500

1.0

Notes to Table 9.15.3.4.:

(1)See Sentence 9.15.3.7.(1).

(2)See Sentences 9.15.3.5.(1).

(3)See Sentence 9.15.3.6.(1).

9.15.3.5. — Adjustments to Footing Widths for Exterior Walls

(1) The strip footing widths for exterior walls shown in Table 9.15.3.4.v1 shall be increased by,

(a) 65 mm for each storey of masonry veneer over wood frame construction supported by the foundation wall,

(b) 130 mm for each storey of masonry construction supported by the foundation wall, and

(c) 150 mm for each storey of flat insulating concrete form wall construction supported by the foundation wall.

Text · e-Laws consolidated snapshot

9.15.3.6. — Adjustments to Footing Widths for Interior Walls

(1) The minimum strip footing widths for interior loadbearing masonry walls shown in Table 9.15.3.4.v1 shall be increased by 100 mm for each storey of masonry construction supported by the footing.

(2) Footings for interior non-loadbearing masonry walls shall be not less than 200 mm wide for walls up to 5.5 m high and the width shall be increased by 100 mm for each additional 2.7 m of height.

Text · e-Laws consolidated snapshot

9.15.3.7. — Adjustments to Footing Area for Columns

(1) The footing area for column spacings other than shown in Table 9.15.3.4.v1 shall be adjusted in proportion to the distance between columns.

Text · e-Laws consolidated snapshot

9.15.3.8. — Footing Thickness

(1) Footing thickness shall be not less than the greater of,

(a) 100 mm, or

(b) the width of the projection of the footing beyond the supported element.

Text · e-Laws consolidated snapshot

9.15.3.9. — Step Footings

(1) Where step footings are used,

(a) the vertical rise between horizontal portions shall not exceed 600 mm, and

(b) the horizontal distance between risers shall be not less than 600 mm.

Text · e-Laws consolidated snapshot

9.15.4. — Foundation Walls

Content not available for this version.

9.15.4.1. — Permanent Form Material

(1) Insulating concrete form units shall be manufactured of polystyrene conforming to the performance requirements of CAN/ULC-S701, “Thermal Insulation, Polystyrene, Boards and Pipe Covering”, for Type 2, 3 or 4 polystyrene.

Text · e-Laws consolidated snapshot

9.15.4.2. — Foundation Wall Thickness and Required Lateral Support

(1) Except as required in Sentence (2), the thickness of foundation walls made of unreinforced concrete block or solid concrete and subject to lateral earth pressure shall conform to Table 9.15.4.2.A. for walls not exceeding 2.5 m in unsupported height.

(2) The thickness of concrete in flat insulating concrete form foundation walls shall be not less than the greater of,

(a) 140 mm, or

(b) the thickness of the concrete in the wall above.

(3) Foundation walls made of flat insulating concrete form units shall be laterally supported at the top and at the bottom.

(4) Where average stable soils are encountered and wind loads on the exposed portion of the foundation are no greater than 0.70 kPa, the thickness and reinforcing of foundation walls made of reinforced concrete block and subject to lateral earth pressure shall conform to Table 9.15.4.2.B. and Sentences (5) to (10).

(5) For concrete block walls required to be reinforced, continuous vertical reinforcement shall,

(a) be provided at wall corners, wall ends, wall intersections, at changes in wall height, at the jambs of all openings and at movement joints,

(b) extend from the top of the footing to the top of the foundation wall,

(c) where foundation walls are laterally unsupported at the top, have not less than 600 mm embedment into the footing, and

(d) where foundation walls are laterally supported at the top, have not less than 50 mm embedment into the footing, if the floor slab does not provide lateral support at the wall base.

(6) Where foundation walls are laterally unsupported, the footing shall be designed according to Part 4 to resist overturning and sliding, if the maximum height of finished ground above the basement floor or crawl space ground cover exceeds 1.50 m.

(7) At the base of concrete block walls required to be reinforced and where the height of finished ground above the basement floor or crawl space ground cover exceeds 2.0 m, not less than one 15M intermediate vertical bar reinforcement shall be installed midway between adjacent continuous vertical reinforcement, and shall,

(a) extend to not less than 600 mm above the top of the footing, and

(b) have not less than 50 mm embedment into the footing, if the floor slab does not provide lateral support at the wall base.

(8) For concrete block walls required to be reinforced, a continuous horizontal bond beam containing at least one 15M bar shall be installed,

(a) along the top of the wall,

(b) at the sill and head of all openings greater than 1.20 m in width, and

(c) at structurally connected floors.

(9) In concrete block walls required to be reinforced, all vertical bar reinforcement shall be installed along the centre line of the wall.

(10) In concrete block walls required to be reinforced, ladder or truss type lateral reinforcement not less than 3.8 mm (No. 9 ASWG) shall be installed in the bed joint of every second masonry course.

Editor's note

As filed in O. Reg. 350/06, Table 9.15.4.2.B. heads its second column 'Colun 2' — an apparent typographical error for 'Column 2' — italicizes the headings of Columns 3 to 6, leaves the heading of the table's notes unbolded, and numbers the notes '(1)', '(2)' and '(3)'. The current e-Laws consolidation corrects the spelling to 'Column 2', removes the italics, bolds the notes heading, and renders the note numbers as superscripts, with no amending regulation making any of these changes. This map preserves the table as filed.

Text · e-Laws consolidated snapshot

Table 9.15.4.2.A. Thickness of Solid Concrete and Unreinforced Concrete Block Foundation Walls Forming Part of Sentence 9.15.4.2.(1)

Column 1

Column 2

Column 3

Column 4

Type of Foundation Wall

Minimum Wall Thickness, Mm

Maximum Height of Finish Ground Above Basement Floor or Crawl Space Ground Cover, m

Foundation Wall Laterally Unsupported at the Top(1)

Foundation Wall Laterally Supported at the Top(1)

Solid concrete, 15 Mpa min. strength

150

0.8

1.5

200

1.2

2.15

250

1.4

2.3

300

1.5

2.3

Solid concrete, 20 Mpa min. strength

150

0.8

1.8

200

1.2

2.3

250

1.4

2.3

300

1.5

2.3

Unreinforced Concrete Block

140

0.6

0.8

190

0.9

1.2

240

1.2

1.8

290

1.4

2.2

Note to Table 9.15.4.2.A.:

(1)See Article 9.15.4.3.

Table 9.15.4.2.B. Reinforced Concrete Block Foundation Walls Forming Part of Sentence 9.15.4.2.(4)

Column 1

Colun 2

Column 3

Column 4

Column 5

Column 6

Minimum Wall Thickness, mm

Maximum Height of Finished Ground above Basement Floor or Crawl Space Ground Cover, m

Foundation Wall Laterally Unsupported at Top (1)

Foundation Wall Laterally Supported at Top (1)

Continuous Vertical Reinforcement

Continuous Vertical Reinforcement

Minimum Bar Size

Maximum Bar Spacing, m

Minimum Bar Size

Maximum Bar Spacing, m

190

1.0

25M

1.2

(2)

(2)

1.2

25M

1.2

(2)

(2)

1.4

25M

1.2

15M

1.2

1.6

25M

0.8

15M

1.2

1.8

25M

0.6

20M

1.2

2.0

25M

0.4

20M

1.2

2.2

(3)

(3)

25M

1.2

2.4

(3)

(3)

25M

1.2

240

1.4

25M

1.0

(2)

(2)

1.6

25M

1.0

(2)

(2)

1.8

25M

0.8

(2)

(2)

2.0

25M

0.8

20M

1.8

2.2

25M

0.8

25M

1.8

2.4

25M

0.6

25M

1.8

Notes to Table 9.15.4.2.B.:

(1)See Article 9.15.4.3.

(2)No reinforcement required.

(3)Design to Part 4.

9.15.4.3. — Foundation Walls Considered to be Laterally Supported at the Top

(1) Sentences (2) to (4) apply to lateral support for walls described in Sentence 9.15.4.2.(1)v1.

(2) Foundation walls shall be considered to be laterally supported at the top if,

(a) such walls support solid masonry superstructure,

(b) the floor joists are embedded in the top of the foundation walls, or

(c) the floor system is anchored to the top of the foundation walls with anchor bolts, in which case the joists may run either parallel or perpendicular to the foundation walls.

(3) Unless the wall around an opening is reinforced to withstand earth pressure, the portion of the foundation wall beneath an opening shall be considered laterally unsupported, if,

(a) the opening is more than 1.2 m wide, or

(b) the total width of the openings in the foundation wall constitutes more than 25% of the length of the wall.

(4) For the purposes of Sentence (3), the combined width of the openings shall be considered as a single opening if the average width is greater than the width of solid wall between them.

(5) Flat insulating concrete form foundation walls shall be considered to be laterally supported at the top if the floor joists are installed according to Article 9.20.17.5.v1

Text · e-Laws consolidated snapshot

9.15.4.4. — Foundation Walls Considered to be Laterally Supported at the Bottom

(1) Flat insulating concrete form foundation walls shall be considered to be laterally supported at the bottom where the foundation wall,

(a) supports backfill not more than 1.2 m in height,

(b) is supported at the footing by a shear key and is supported at the top by the ground floor framing, or

(c) is dowelled to the footing with not less than 15M bars spaced not more than 1.2 m o.c.

Text · e-Laws consolidated snapshot

9.15.4.5. — Reinforcement for Flat Insulating Concrete Form Foundation Walls

(1) Horizontal reinforcement in flat insulating concrete form foundation walls shall,

(a) consist of,

(i) one 10M bar placed not more than 300 mm from the top of the wall, and

(ii) 10M bars spaced not more than 600 mm o.c., and

(b) be located,

(i) in the inside half of the wall section, and

(ii) with a minimum cover of 30 mm from the inside face of the concrete.

(2) Vertical wall reinforcement in flat insulating concrete form foundation walls shall,

(a) conform to,

(i) Table 9.15.4.5.A. for 140 mm walls,

(ii) Table 9.15.4.5.B. for 190 mm walls, and

(iii) Table 9.15.4.5.C. for 240 mm walls,

(b) be located in the inside half of the wall section with a minimum cover of 30 mm from the inside face of the concrete wall, and

(c) where interrupted by wall openings, be placed not more than 600 mm from each side of the openings.

(3) Cold joints in flat insulating concrete form foundation walls shall be reinforced with at least one 15M bar spaced not more than 600 mm o.c. and embedded not less than 300 mm on both sides of the joint.

(4) Reinforcing around openings in flat insulating concrete form foundation walls shall comply with Articles 9.20.17.3.v1v2 or 9.20.17.4.

Text · e-Laws consolidated snapshot

Table 9.15.4.5.A. Vertical Reinforcement for 140 mm Flat Insulating Concrete Form Foundation Walls Forming Part of Sentence 9.15.4.5.(2)

Column 1

Column 2

Column 3

Column 4

Maximum Height of Finished Ground Above Finished Basement Floor, m

Maximum Vertical Reinforcement

Maximum Unsupported Basement Wall Height

2.44 m

2.75 m

3.00 m

1.35

10M at 400 mm o.c.

10M at 400 mm o.c.

10M at 400 mm o.c.

1.60

10M at 400 mm o.c.

10M at 380 mm o.c.

10M at 380 mm o.c.

2.00

10M at 380 mm o.c.

10M at 380 mm o.c.

10M at 380 mm o.c.

2.20

10M at 250 mm o.c.

10M at 250 mm o.c.

10M at 250 mm o.c.

2.35

n/a

10M at 250 mm o.c.

10M at 250 mm o.c.

2.60

n/a

10M at 250 mm o.c.

10M at 250 mm o.c.

3.00

n/a

n/a

15M at 250 mm o.c.

Table 9.15.4.5.B. Vertical Reinforcement for 190 mm Flat Insulating Concrete Form Foundation Walls Forming Part of Sentence 9.15.4.5.(2)

Column 1

Column 2

Column 3

Column 4

Maximum Height of Finished Ground Above Finished Basement Floor, m

Maximum Vertical Reinforcement

Maximum Unsupported Basement Wall Height

2.44 m

2.75 m

3.00 m

2.20

none required

10M at 400 mm o.c.

10M at 400 mm o.c.

2.35

n/a

10M at 300 mm o.c.

10M at 300 mm o.c.

2.60

n/a

10M at 300 mm o.c.

15M at 400 mm o.c.

3.00

n/a

n/a

15M at 400 mm o.c.

Table 9.15.4.5.C. Vertical Reinforcement for 240 mm Flat Insulating Concrete Form Foundation Walls Forming Part of Sentence 9.15.4.5.(2)

Column 1

Column 2

Column 3

Column 4

Maximum Height of Finished Ground Above Finished Basement Floor, m

Maximum Vertical Reinforcement

Maximum Unsupported Basement Wall Height

2.44 m

2.75 m

3.00 m

2.20

none required

none required

none required

2.60

n/a

15M at 400 mm o.c.

15M at 400 mm o.c.

3.00

n/a

n/a

15M at 400 mm o.c.

9.15.4.6. — Extension above Ground Level

(1) Exterior foundation walls shall extend not less than 150 mm above finished ground level.

Text · e-Laws consolidated snapshot

9.15.4.7. — Reduction in Thickness

(1) Where the top of a foundation wall is reduced in thickness to permit the installation of floor joists, the reduced section shall be not more than 350 mm high and not less than 90 mm thick.

(2) Where the top of a foundation wall is reduced in thickness to permit the installation of a masonry exterior facing, the reduced section shall be,

(a) not less than 90 mm thick, and

(b) tied to the facing material with metal ties conforming to Sentence 9.20.9.4.(3) spaced not more than,

(i) 200 mm o.c. vertically, and

(ii) 900 mm o.c. horizontally.

(3) The space between wall and facing described in Sentence (2) shall be filled with mortar.

Text · e-Laws consolidated snapshot

9.15.4.8. — Corbelling

(1) Corbelling of masonry foundation walls supporting cavity walls shall conform to Article 9.20.12.2.

Text · e-Laws consolidated snapshot

9.15.4.9. — Crack Control Joints

(1) Crack control joints shall be provided in foundation walls more than 25 m long at intervals of not more than 15 m.

(2) Joints required in Sentence (1) shall be designed to resist moisture penetration and shall be keyed to prevent relative displacement of the wall portions adjacent to the joint.

Text · e-Laws consolidated snapshot

9.15.4.10. — Interior Masonry Walls

(1) Interior masonry foundation walls not subject to lateral earth pressure shall conform to Section 9.20.

Text · e-Laws consolidated snapshot

9.15.5. — Support of Joists and Beams on Masonry Foundation Walls

Content not available for this version.

9.15.5.1. — Support of Floor Joists

(1) Except as permitted in Sentence (2), foundation walls of hollow unit masonry supporting floor joists shall be,

(a) capped with not less than 50 mm of solid masonry or concrete, or

(b) have the top course filled with mortar or concrete.

(2) Capping required in Sentence (1) is permitted to be omitted,

(a) in localities where termites are not known to occur,

(b) when the joists are supported on a wood plate not less than 38 mm by 89 mm, and

(c) when the siding overlaps the foundation wall not less than 12 mm.

Text · e-Laws consolidated snapshot

9.15.5.2. — Support of Beams

(1) Not less than a 190 mm depth of solid masonry shall be provided beneath beams supported on masonry.

(2) Where the beam referred to in Sentence (1) is supported below the top of the foundation walls, the ends of such beams shall be protected from the weather.

Text · e-Laws consolidated snapshot

9.15.5.3. — Pilasters

(1) Pilasters shall be provided under beams that frame into unit masonry foundation walls 140 mm or less in thickness.

(2) Pilasters required in Sentence (1) shall be not less than 90 mm by 290 mm and shall be bonded or tied into the wall.

(3) The top 200 mm of pilasters required in Sentence (1) shall be solid.

Text · e-Laws consolidated snapshot

9.15.6. — Parging and Finishing of Foundation Walls

Content not available for this version.

9.15.6.1. — Foundation Walls Below Ground

(1) Concrete block foundation walls shall be parged on the exterior face below ground level as required in Section 9.13.

Text · e-Laws consolidated snapshot

9.15.6.2. — Foundation Walls Above Ground

(1) Exterior surfaces of concrete block foundation walls above ground level shall have tooled joints, or shall be rendered, parged or otherwise suitably finished.

Text · e-Laws consolidated snapshot

9.15.6.3. — Form Ties

(1) All form ties shall be removed at least flush with the concrete surface.

Text · e-Laws consolidated snapshot