Division B
Acceptable Solutions

Part 9 — Housing and Small Buildings

Section 9.20. Masonry and Insulating Concrete Form Walls Not In Contact with the Ground

9.20.1. Application

9.20.1.1. General
1) Intent StatementExcept as provided in Article 9.20.1.2., this Section applies to
a) unreinforced masonry and masonry veneer walls not in contact with the ground, where
i) the height of the walls constructed on the foundation walls does not exceed 11 m, and
ii) the roof or floor assembly above the first storey is not of concrete construction, and
b) flat insulating concrete form walls not in contact with the ground that (see A-9.15.1.1.(1)(c) and 9.20.1.1.(1)(b) in Appendix A)
i) have a maximum floor-to-floor height of 3 m,
ii) are erected in buildings not more than 2 storeys in building height and containing only a single dwelling unit, and
iii) are erected in locations where the seismic spectral response acceleration, Sa(0.2), is not greater than 0.4 (see A-9.20.1.2. in Appendix A).
2) Intent StatementFor walls other than those described in Sentence (1), or where the masonry walls or insulating concrete form walls not in contact with the ground are designed for specified loads on the basis of ultimate and serviceability limit states, Subsection 4.3.2. shall apply.
9.20.1.2. Earthquake Reinforcement
(See Appendix A.)
1) Intent StatementIn locations where the spectral response acceleration, Sa(0.2), is greater than 0.55, loadbearing elements of masonry buildings more than 1 storey in building height shall be reinforced with not less than the minimum amount of reinforcement required by Subsection 9.20.15.
2) Intent StatementIn locations where the spectral response acceleration, Sa(0.2), is greater than 0.35 but less than or equal to 0.55, loadbearing elements of masonry buildings 3 storeys in building height shall be reinforced with not less than the minimum amount of reinforcement required by Subsection 9.20.15.

9.20.2. Masonry Units

9.20.2.1. Masonry Unit Standards
1) Masonry units shall comply with
a) change beginASTM C 73, “Calcium Silicate Brick (Sand-Lime Brick),”change end
b) ASTM C 126, “Ceramic Glazed Structural Clay Facing Tile, Facing Brick, and Solid Masonry Units,”
c) ASTM C 212, “Structural Clay Facing Tile,”
d) CAN/CSA-A82.1-M, “Burned Clay Brick (Solid Masonry Units Made from Clay or Shale),”
e) CAN/CSA-A82.4-M, “Structural Clay Load-Bearing Wall Tile,”
f) CSA A82.5-M, “Structural Clay Non-Load-Bearing Tile,”
g) CAN3-A82.8-M, “Hollow Clay Brick,”
h) CAN/CSA-A165.1, “Concrete Block Masonry Units,”
i) CAN/CSA-A165.2, “Concrete Brick Masonry Units,”
j) CAN/CSA-A165.3, “Prefaced Concrete Masonry Units,” or
k) CAN3-A165.4-M, “Autoclaved Cellular Units.”

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9.20.2.2. Used Brick
1) Intent StatementUsed bricks shall be free of old mortar, soot or other surface coating and shall conform to Article 9.20.2.1.
9.20.2.3. Glass Blocks
1) Intent StatementGlass blocks shall not be used as loadbearing units or in the construction of fireplaces or chimneys.
9.20.2.4. Cellular Concrete
1) Intent StatementMasonry made with cellular concrete shall not be used in contact with the soil or exposed to the weather.
9.20.2.5. Stone
1) Stone shall be sound and resistant to deterioration.

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9.20.2.6. Concrete Blocks Exposed to the Weather
1) Intent StatementConcrete blocks exposed to the weather shall have density and water absorption characteristics conforming to concrete types A, B, C, or D described in CAN/CSA-A165.1, “Concrete Block Masonry Units.”
9.20.2.7. Compressive Strength
1) Intent StatementThe compressive strength of concrete blocks shall conform to Table 9.20.2.7.
Table 9.20.2.7.
Compressive Strength of Concrete Blocks
Forming part of Sentence 9.20.2.7.(1)
Type of Unit Minimum Compressive Strength Over Net Area, MPa
Exposed to Weather Not Exposed to Weather
Solid or hollow concrete blocks 15 10

Solid loadbearing cellular blocks

Not permitted 5

Solid non-loadbearing cellular blocks

Not permitted 2

9.20.3. Mortar and Grout

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9.20.3.1. Materials

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1) Intent StatementCementitious materials and aggregates for mortar and grout shall comply with CAN/CSA-A179, “Mortar and Grout for Unit Masonry.”
2) Intent StatementWater and aggregate shall be clean and free of significant amounts of deleterious materials.
3) Intent StatementLime used in mortar shall be hydrated.
4) Intent StatementIf lime putty is used in mortar, it shall be made by slaking quicklime in water for not less than 24 h or soaking hydrated lime in water for not less than 12 h.
9.20.3.2. Mortar and Grout Mixes
1) Intent StatementMortar types shall be in accordance with Table 9.20.3.2.A
2) Intent StatementMortar for glass block masonry shall be
a) Type S Portland cement-lime where exposed to the exterior, or
b) Type S or N where protected from the exterior.
3) Intent StatementMortar shall be mixed within the proportion limits provided in Table 9.20.3.2.B, with sufficient water to bring the mixture to a consistency adequate for laying masonry units.
4) Intent StatementGrout shall be mixed within the proportion limits provided in Table 9.20.3.2.C, with sufficient water to provide a suitable flow to fill all voids completely, without excessive segregation or bleeding.
5) Intent StatementExcept as provided in Sentence (6), mortar shall be used and placed in final position
a) within 1.5 h after mixing when the air temperature is 25°C or higher, or
b) within 2.5 h after mixing when the air temperature is less than 25°C.
6) Intent StatementMortar and grout containing a set-control admixture shall be manufactured off-site in a batching plant and shall be used and placed in final position within a time not exceeding the useful life stipulated by the manufacturer.
7) Intent StatementGrout used for reinforced masonry shall be placed in accordance with the requirements of CAN/CSA-A371, “Masonry Construction for Buildings.”
Table 9.20.3.2.A
Mortar Use
Forming part of Sentence 9.20.3.2.(1)
Location

Building Element

Mortar Type
Exterior, Above Ground

Loadbearing walls and columns

S

Non-loadbearing walls and columns

N or S

Parapets, chimneys, masonry veneer

N or S
Exterior, At or Below Ground

Foundation walls and columns

S
Interior

Loadbearing walls and columns

N

Non-loadbearing walls and columns

N
Table 9.20.3.2.B
Mortar Mix Proportions (by volume)
Forming part of Sentence 9.20.3.2.(3)
Mortar Type Portland Cement Lime Masonry Cement Type N Masonry Cement Type S Fine Aggregate (damp, loose-state sand)
Type S 1 ½ - - 3½ to 4½
- - - 1 2¼ to 3
½ - 1 - 3½ to 4½
Type N 1 1 - - 4½ to 6
- - 1 - 2¼ to 3
Table 9.20.3.2.C
Grout Mix Proportions (by volume)
Forming part of Sentence 9.20.3.2.(4)
Portland Cement Lime Fine Aggregate (sand) Coarse Aggregate
1 0 to 1/10 2¼ to 3 times the sum of the cement and lime volumes 1 to 2 times the sum of the cement and lime volumes

9.20.4. Mortar Joints

9.20.4.1. Thickness
1) Intent StatementExcept as provided in Sentence (2), mortar joint thickness for burned clay brick and concrete masonry units shall be 10 mm.
2) Intent StatementPermitted tolerances in head and bed joints shall be not more than ± 5 mm.
9.20.4.2. Solid Masonry Units
1) Intent StatementSolid masonry units shall be laid with full head and bed joints.
9.20.4.3. Laying of Masonry Units
1) Intent StatementHollow masonry units shall be laid with mortar applied to head and bed joints of both inner and outer face shells.
2) Intent StatementVertically aligned webs of hollow masonry units shall be laid in a full bed of mortar
a) under the starting course,
b) in all courses of columns, and
c) where adjacent to cells or cavities that are to be filled with grout.
3) Intent StatementExcept for head joints left open for weep holes and ventilation, solid masonry units shall be laid with full head and bed joints.

9.20.5. Masonry Support

9.20.5.1. Masonry Support
1) Intent StatementAll masonry shall be supported on masonry, concrete or steel, except that masonry veneer walls may be supported on foundations of wood frame constructed in conformance with Sentence 9.15.2.4.(1). (See Appendix A.)
2) Intent StatementEvery masonry wall shall be at least as thick as the wall it supports, except as otherwise permitted in Article 9.20.12.2.
9.20.5.2. Lintels or Arches
1) Intent StatementMasonry over openings shall be supported by steel, masonry or reinforced concrete lintels, or masonry arches.
2) Intent StatementSteel angle lintels supporting masonry veneer above openings shall
a) conform to Table 9.20.5.2., and
b) have a bearing length not less than 90 mm.
Table 9.20.5.2.
Maximum Allowable Spans for Steel Lintels Supporting Masonry Veneer
Forming part of Sentence 9.20.5.2.(2)

Minimum Angle Size, mm (in.)

Maximum Allowable Spans, m (ft.-in.)
Vertical Leg Horizontal Leg Thickness

Supporting
75 mm
(3 in.) Brick

Supporting
90 mm
(3½ in.) Brick

Supporting
100 mm
(4 in.) Stone

change begin89 (3½)change end

change begin76 (3)change end

change begin6.4 (¼)change end

2.55 (8-4)

 — —

change begin89 (3½)change end

change begin89 (3½)change end

change begin6.4 (¼)change end

2.59 (8-6)

2.47 (8-1)

2.30 (7-7)

change begin102 (4)change end

change begin89 (3½)change end

change begin6.4 (¼)change end

2.79 (9-2)

2.66 (8-9)

2.48 (8-2)

change begin127 (4⅞) change end

change begin89 (3½)change end

change begin7.9 (5/16)change end

3.47 (11-5)

3.31 (10-10)

3.08 (10-1)

change begin127 (4⅞) change end

change begin89 (3½)change end

change begin11 (⅜)change end

3.64 (11-11)

3.48 (11-5)

3.24 (10-8)
3) Intent StatementSteel angle lintels supporting masonry other than veneer, masonry and reinforced concrete lintels, and masonry arches shall be designed in accordance with Part 4 to support the imposed load.
4) Intent StatementSteel angle lintels supporting masonry shall be prime painted or otherwise protected from corrosion.

9.20.6. Thickness and Height

9.20.6.1. Thickness of Exterior Walls
1) Intent StatementMasonry exterior walls, other than cavity walls, in 1-storey buildings and the top storeys of 2- and 3-storey  buildings shall be not less than 140 mm thick, provided the walls are not more than 2.8 m high at the eaves and 4.6 m high at the peaks of gable ends.
2) Intent StatementThe exterior walls of the bottom storeys of 2-storey buildings, and exterior walls of the bottom 2 storeys of 3-storey buildings shall be not less than 190 mm thick.
3) Intent StatementIn exterior walls composed of more than one wythe, each wythe shall be not less than 90 mm thick.
9.20.6.2. Cavity Walls
1) Intent StatementCavity walls shall be made with not less than 90 mm wide units if the joints are raked and not less than 75 mm wide units if the joints are not raked.
2) Intent StatementThe width of a cavity in a cavity wall shall be not less than 50 mm and not greater than 150 mm.
3) Intent StatementThe minimum thickness of cavity walls above the supporting base shall be 230 mm for the top 7.6 m and 330 mm for the remaining portion, except that where 75 mm wide units are used, the wall height above the top of the foundation wall shall not exceed 6 m.
9.20.6.3. Thickness of Interior Walls
1) Intent StatementThe thickness of loadbearing interior walls shall be determined on the basis of the maximum lateral support spacing as provided in Sentences 9.20.10.1.(2) and (3).
2) Intent StatementThe thickness of interior non-loadbearing walls shall be
a) determined on the basis of the maximum lateral support spacing as provided in Sentences 9.20.10.1.(2) and (3), and
b) in any case, not less than 65 mm.
9.20.6.4. Masonry Veneer
1) Intent StatementExcept for masonry veneer where each masonry unit is supported individually by the structural backing, masonry veneer shall be of solid units not less than 75 mm thick.
2) Intent StatementVeneer described in Sentence (1) over wood-frame walls shall have not less than a 25 mm air space behind the veneer.
3) Intent StatementMasonry veneer less than 90 mm thick shall have unraked joints.
4) Intent StatementMasonry veneer shall conform to Subsection 4.3.2., where the masonry units are required to be individually supported by the structural backing.
9.20.6.5. Parapet Walls
1) Intent StatementThe height of parapet walls above the adjacent roof surface shall be not more than 3 times the parapet wall thickness.
2) Intent StatementParapet walls shall be solid from the top of the parapet to not less than 300 mm below the adjacent roof level.
9.20.6.6. Stone or Concrete Facings
1) Intent StatementSlab and panel facings of precast concrete and natural or artificial stone shall conform to Subsection 4.3.2.

9.20.7. Chases and Recesses

9.20.7.1. Maximum Dimensions
1) Intent StatementExcept as permitted in Sentence 9.20.7.2.(2) and Article 9.20.7.4., the depth of any chase or recess shall not exceed one third the thickness of the wall, and the width of the chase or recess shall not exceed 500 mm.
9.20.7.2. Minimum Wall Thickness
1) Intent StatementExcept as permitted in Sentence (2) and Article 9.20.7.4., no chase or recess shall be constructed in any wall 190 mm or less in thickness.
2) Intent StatementRecesses may be constructed in 190 mm walls provided they do not exceed 100 mm in depth, 750 mm in height and 500 mm in width.
9.20.7.3. Separation of Chases or Recesses
1) Intent StatementChases and recesses shall be not less than
a) 4 times the wall thickness apart, and
b) 600 mm away from any pilaster, cross wall, buttress or other vertical element providing required lateral support for the wall.
9.20.7.4. Non-Conforming Chases or Recesses
1) Intent StatementChases or recesses that do not conform to the limits specified in Articles 9.20.7.1. to 9.20.7.3. shall be considered as openings, and any masonry supported above such a chase or recess shall be supported by a lintel or arch as provided in Article 9.20.5.2.
9.20.7.5. Chases or Recesses Cut into Walls
1) Intent StatementChases and recesses shall not be cut into walls made with hollow units after the masonry units are in place.

9.20.8. Support of Loads

9.20.8.1. Capping of Hollow Masonry Walls
1) Intent StatementExcept as permitted in Sentence (2), loadbearing walls of hollow masonry units supporting roof or floor framing members shall be capped with not less than 50 mm of solid masonry or have the top course filled with concrete.
2) Intent StatementCapping required in Sentence (1) may be omitted where the roof framing is supported on a wood plate not less than 38 mm by 89 mm.
9.20.8.2. Cavity Walls Supporting Framing Members
1) Intent StatementFloor joists supported on cavity walls shall be supported on solid units not less than 57 mm high.
2) Intent StatementFloor joists described in Sentence (1) shall not project into the cavity.
3) Intent StatementRoof and ceiling framing members bearing on cavity walls shall be supported on
a) not less than 57 mm of solid masonry, bridging the full thickness of the wall, or
b) a wood plate not less than 38 mm thick, bearing not less than 50 mm on each wythe.
9.20.8.3. Bearing of Beams and Joists
1) Intent StatementThe bearing area under beams and joists shall be sufficient to carry the supported load.
2) Intent StatementIn no case shall the minimum length of end bearing of beams supported on masonry be less than 90 mm.
3) Intent StatementThe length of end bearing of floor, roof or ceiling joists supported on masonry shall be not less than 40 mm.
9.20.8.4. Support of Beams and Columns
1) Intent StatementBeams and columns supported on masonry walls shall be supported on pilasters where the thickness of the masonry wall or wythe is less than 190 mm.
2) Intent StatementNot less than 190 mm depth of solid masonry or concrete shall be provided under the beam or column referred to in Sentence (1).
3) Intent StatementPilasters required in Sentence (1) shall be bonded or tied to masonry walls.
4) Intent StatementConcrete pilasters required in Sentence (1) shall be not less than 50 mm by 300 mm.
5) Intent StatementUnit masonry pilasters required in Sentence (1) shall be not less than 100 mm by 290 mm.
9.20.8.5. Distance to Edge of Supporting Members
(See Appendix A.)
1) Intent StatementMasonry veneer of hollow units resting on a bearing support shall not project more than
a) 30 mm beyond the supporting base where the veneer is not less than 90 mm thick, and
b) 12 mm beyond the supporting base where the veneer is less than 90 mm thick.
2) Intent StatementMasonry veneer of solid units resting on bearing support shall not project more than one third of the width of the veneer.
3) Intent StatementWhere the masonry veneer described in Sentence (2) is rough stone masonry,
a) the projection shall be measured as the average projection of the units, and
b) the width of the veneer shall be measured as the average width of the veneer.

9.20.9. Bonding and Tying

9.20.9.1. Joints to be Offset or Reinforced
1) Intent StatementVertical joints in adjacent masonry courses shall be offset unless each wythe of masonry is reinforced with the equivalent of not less than 2 corrosion-resistant steel bars of 3.76 mm diam placed in the horizontal joints at vertical intervals not exceeding 460 mm.
2) Intent StatementWhere joints in the reinforcing referred to in Sentence (1) occur, the bars shall be lapped not less than 150 mm.
9.20.9.2. Bonding or Tying of Other than Masonry Veneer
1) Intent StatementExcept as provided in Article 9.20.9.5. regarding masonry veneer, masonry walls that consist of 2 or more wythes shall have the wythes bonded or tied together with masonry bonding units as described in Article 9.20.9.3. or with metal ties as described in Article 9.20.9.4.
9.20.9.3. Bonding
1) Intent StatementWhere wythes are bonded together with masonry units, the bonding units shall comprise not less than 4% of the wall surface area.
2) Intent StatementBonding units described in Sentence (1) shall be spaced not more than 600 mm vertically and horizontally in the case of brick masonry and 900 mm o.c. in the case of block or tile.
3) Intent StatementUnits described in Sentence (1) shall extend not less than 90 mm into adjacent wythes.
9.20.9.4. Tying
1) Intent StatementWhere 2 or more wythes are tied  together with metal ties of the individual rod type, the ties shall conform to the requirements in Sentences (3) to (6).
2) Intent StatementOther ties may be used where it can be shown that such ties provide walls that are at least as strong and as durable as those made with the individual rod type.
3) Intent StatementMetal ties of the individual rod type shall
a) be corrosion-resistant,
b) have a minimum cross-sectional area of not less than 17.8 mm2, and
c) have not less than a 50 mm portion bent at right angles at each end.
4) Intent StatementMetal ties of the individual rod type shall
a) extend from within 25 mm of the outer face of the wall to within 25 mm of the inner face of the wall,
b) be completely embedded in mortar except for the portion exposed in cavity walls, and
c) be staggered from course to course.
5) Intent StatementWhere 2 or more wythes in walls other than cavity walls and masonry veneer/masonry backing walls are tied together with metal ties of the individual rod type, the space between wythes shall be completely filled with mortar.
6) Intent StatementTies described in Sentence (5) shall be
a) located within 300 mm of openings and spaced not more than 900 mm apart around openings, and
b) spaced not more than 900 mm apart horizontally and 460 mm apart vertically at other locations.
7) Intent StatementExcept as required in Sentences (8) and (9), where the inner and outer wythes of cavity walls are tied with individual wire ties, the ties shall be spaced not more than 900 mm apart horizontally and 400 mm apart vertically.
8) Intent StatementWithin 100 mm of the bottom of each floor or roof assembly where the cavity extends below the assemblies, the ties described in Sentence (7) shall be spaced not more than 600 mm apart horizontally.
9) Intent StatementWithin 300 mm of any openings, the ties described in Sentence (7) shall be spaced not more than 900 mm apart.
9.20.9.5. Ties for Masonry Veneer
1) Intent StatementMasonry veneer 75 mm or more in thickness and resting on a bearing support shall be tied to masonry backing or to wood framing members with straps that are
a) corrosion-resistant,
b) not less than 0.76 mm thick,
c) not less than 22 mm wide,
d) shaped to provide a key with the mortar, and
e) spaced in accordance with Table 9.20.9.5.
Table 9.20.9.5.
Veneer Tie Spacing
Forming part of Sentence 9.20.9.5.(1)
Maximum Vertical Spacing, mm Maximum Horizontal Spacing, mm
400 800
500 600
600 400
2) Intent StatementStraps described in Sentence (1) that are fastened to wood framing members shall be
a) bent at a right angle within 6 mm from the fastener, and
b) fastened with corrosion-resistant 3.18 mm diam screws or spiral nails having a wood penetration of not less than 63 mm.
3) Intent StatementMasonry veneer individually supported by masonry or wood-frame backing shall be secured to the backing in conformance with Subsection 4.3.2.
9.20.9.6. Reinforcing for Glass Block
1) Intent StatementGlass block shall have horizontal joint reinforcement of 2 corrosion-resistant bars of not less than 3.76 mm diam or expanded metal strips not less than 75 mm wide
a) spaced at vertical intervals of not more than 600 mm for units 200 mm or less in height, and
b) installed in every horizontal joint for units higher than 200 mm.
2) Intent StatementReinforcement required in Sentence (1) shall be lapped not less than 150 mm.

9.20.10. Lateral Support

9.20.10.1. Lateral Support Required
1) Intent StatementMasonry walls shall be laterally supported by floor or roof construction or by intersecting masonry walls or buttresses.
2) Intent StatementThe spacing of supports required in Sentence (1) shall be not more than
a) 20 times the wall thickness for all loadbearing walls and exterior non-loadbearing walls, and
b) 36 times the wall thickness for interior non-loadbearing walls.
3) Intent StatementIn applying Sentence (2), the thickness of cavity walls shall be taken as the greater of
a) two-thirds of the sum of the thicknesses of the wythes, or
b) the thickness of the thicker wythe.
4) Intent StatementFloor and roof constructions providing lateral support for walls as required in Sentence (1) shall be constructed to transfer lateral loads to walls or buttresses approximately at right angles to the laterally supported walls.

9.20.11. Anchorage of Roofs, Floors and Intersecting Walls

9.20.11.1. Anchorage to Floor or Roof Assemblies where Masonry Walls Require Lateral Support
1) Intent StatementWhere required to receive lateral support (see Subsection 9.20.10.), masonry walls shall be anchored to each floor or roof assembly at maximum intervals of 2 m, except that anchorage to floor joists not more than 1 m above grade may be omitted.
2) Intent StatementAnchors required in Sentence (1) shall be corrosion-resistant and be not less than the equivalent of 40 mm by 4.76 mm thick steel straps.
3) Intent StatementAnchors required in Sentence (1) shall be shaped to provide a mechanical key with the masonry and shall be securely fastened to the horizontal support to develop the full strength of the anchor.
4) Intent StatementWhen joists are parallel to the wall, anchors required in Sentence (1) shall extend across not less than 3 joists.
9.20.11.2. Bonding and Tying Intersecting Masonry Walls where Walls Require Lateral Support
1) Intent StatementWhere required to provide lateral support, intersecting walls shall be bonded or tied together.
2) Intent StatementWhere bonding is used to satisfy the requirements of Sentence (1), 50% of the adjacent masonry units in the intersecting wall, distributed uniformly over the height of the intersection, shall be embedded in the laterally supported wall.
3) Intent StatementWhere tying is used to satisfy the requirements of Sentence (1), the ties shall be
a) corrosion-resistant metal,
b) equivalent to not less than 4.76 mm by 40 mm steel strapping,
c) spaced not more than 800 mm o.c. vertically, and
d) shaped at both ends to provide sufficient mechanical key to develop the strength of the ties.
9.20.11.3. Anchoring Intersecting Wood-Frame Walls to Masonry Walls
1) Intent StatementWood-frame walls shall be anchored to masonry walls that they intersect with not less than 4.76 mm diam corrosion-resistant steel rods spaced not more than 900 mm o.c. vertically.
2) Intent StatementAnchors required in Sentence (1) shall be fastened to the wood framing at one end and shaped to provide a mechanical key at the other end to develop the strength of the anchor.
9.20.11.4. Anchoring Wood-Frame Roof Systems to Masonry Walls
1) Intent StatementExcept as permitted in Sentence (2), roof systems of wood-frame construction shall be anchored to exterior masonry walls by not less than 12.7 mm diam anchor bolts,
a) spaced not more than 2.4 m apart,
b) embedded not less than 90 mm into the masonry, and
c) fastened to a rafter plate of not less than 38 mm thick lumber.
2) Intent StatementThe roof system described in Sentence (1) is permitted to be anchored by nailing the wall furring strips to the side of the rafter plate.
9.20.11.5. Anchoring Masonry Cornices, Sills and Trim to Masonry Walls
1) Intent StatementCornices, sills or other trim of masonry material which project beyond the wall face shall have not less than 65% of their mass, but not less than 90 mm, within the wall or shall be adequately anchored to the wall with corrosion-resistant anchors.
9.20.11.6. Anchoring to Masonry Piers
1) Intent StatementWhere anchor bolts are to be placed in the top of a masonry pier, the pier shall conform to the requirements of Sentence 9.15.2.3.(4) and shall be capped with concrete or reinforced masonry not less than 200 mm thick.

9.20.12. Corbelling

9.20.12.1. Corbelling
1) Intent StatementAll corbelling shall consist of solid units.
2) Intent StatementThe units referred to in Sentence (1) shall be corbelled so that the horizontal projection of any unit does not exceed 25 mm and the total projection does not exceed one third of the total wall thickness.
9.20.12.2. Corbelling for Cavity Walls
1) Intent StatementCavity walls of greater thickness than the foundation wall on which they rest shall not be corbelled but may project 25 mm over the outer face of the foundation wall disregarding parging.
2) Intent StatementWhere the foundation wall referred to in Sentence (1) is unit masonry, it is permitted to be corbelled to meet flush with the inner face of a cavity wall provided
a) the projection of each course does not exceed half the height or one third the width of the corbelled unit, and
b) the total corbel does not exceed one third of the foundation wall thickness.
(See Appendix A.)
9.20.12.3. Corbelling for Masonry Veneer
1) Intent StatementMasonry veneer resting on a bearing support shall not project more than 25 mm beyond the supporting base where the veneer is not less than 90 mm thick, and 12 mm beyond the supporting base where the veneer is less than 90 mm thick.
2) Intent StatementIn the case of rough stone veneer, the projection, measured as the average projection of the stone units, shall not exceed one-third the bed width beyond the supporting base.

9.20.13. Control of Rainwater Penetration

9.20.13.1. Materials for Flashing
1) Intent StatementMaterials used for flashing shall conform to Table 9.20.13.1.
Table 9.20.13.1.
Flashing Materials
Forming part of Sentence 9.20.13.1.(1)
Material Minimum Thickness, mm
Exposed Flashing Concealed Flashing
Aluminum 0.48 —
Copper 0.46 0.46
Copper or aluminum laminated to felt or kraft paper — 0.05
Galvanized steel 0.33 0.33
Lead sheet 1.73 1.73
Polyethylene — 0.50
Roll roofing, Type S — standard
Zinc 0.46 0.46
2) Intent StatementAluminum flashing in contact with masonry or concrete shall be effectively coated or separated from the masonry or concrete by an impervious membrane.
9.20.13.2. Fastening of Flashing
1) Intent StatementFastening devices for flashing shall be corrosion-resistant and, where metal flashing is used, shall be compatible with the flashing with respect to galvanic action.
9.20.13.3. Location of Flashing
1) Intent StatementFlashing shall be installed in masonry and masonry veneer walls
a) beneath jointed masonry window sills,
b) over the back and top of parapet walls,
c) over the heads of glass block panels,
d) beneath weep holes, and
e) over the heads of window or door openings in exterior walls when the vertical distance between the top of a window or door frame and the bottom edge of the eave exceeds one-quarter of the horizontal eave overhang.
9.20.13.4. Extension of Flashing
1) Intent StatementWhen installed beneath jointed masonry window sills or over the heads of openings, flashing shall extend from the front edge of the masonry up behind the sill or lintel.
9.20.13.5. Flashing for Weep Holes in Masonry/Masonry Walls
1) Intent StatementFlashing beneath weep holes in cavity walls and masonry veneer/masonry backing walls shall
a) be bedded not less than 25 mm in the inside wythe,
b) extend to not less than 5 mm beyond the outer face of the building element below the flashing, and
c) be installed with a nominally horizontal slope toward the outside wythe.
9.20.13.6. Flashing for Weep Holes in Masonry Veneer
1) Intent StatementFlashing beneath weep holes in masonry veneer over masonry backing walls shall conform to the flashing requirements for cavity walls and masonry veneer/masonry backing walls in Article 9.20.13.5.
2) Intent StatementFlashing beneath weep holes in masonry veneer over wood-frame walls shall be installed so that it extends from a point not less than 5 mm beyond the outer face of the building element below the flashing to a point 150 mm up the wood-frame wall.
3) Intent StatementWhere the frame wall is sheathed with a sheathing membrane, a non-wood-based rigid exterior insulating sheathing or a semi-rigid insulating sheathing with an integral sheathing membrane, the flashing shall be installed behind the sheathing membrane or insulating sheathing.
4) Intent StatementFlashing described in Sentence (2) is permitted to conform to the requirements for concealed flashing in Table 9.20.13.1.
9.20.13.7. Flashing Joints
1) Intent StatementJoints in flashing shall be made watertight.
9.20.13.8. Required Weep Holes
1) Intent StatementWeep holes spaced not more than 800 mm apart shall be provided at the bottom of
a) cavities in cavity walls, and
b) cavities or air spaces in masonry veneer walls.
2) Intent StatementThe cavities or air spaces described in Sentence (1) shall include those above lintels over window and door openings required to be flashed in conformance with Article 9.20.13.3.
9.20.13.9. Protection of Interior Finish
1) Intent Statement Except as provided in Sentence (3), where the interior finish of the exterior walls of a building is a type that may be damaged by moisture, exterior masonry walls, other than cavity walls or walls that are protected for their full height by a roof of a carport or porch, shall be covered on the interior surface with sheathing membrane conforming to CAN/CGSB-51.32-M, “Sheathing, Membrane, Breather Type,” lapped not less than 100 mm at the joints.
2) Intent StatementIn situations described in Sentence (1), flashing shall be provided where water will accumulate, to lead it to the exterior.
3) Intent StatementWhere insulation that effectively limits the passage of water is applied by a waterproof adhesive or mortar directly to parged masonry, the requirements for sheathing membrane in Sentence (1) do not apply. (See Appendix A.)
9.20.13.10. Mortar Droppings
1) Intent StatementCavity walls shall be constructed so that mortar droppings are prevented from forming a bridge to allow the passage of rain water across the cavity.
9.20.13.11. Caulking at Door and Window Frames
1) Intent StatementThe junction of door and window frames with masonry shall be caulked in conformance with Subsection 9.27.4.
9.20.13.12. Drips beneath Window Sills
1) Intent StatementWhere no flashing is installed beneath window sills, such sills shall be provided with a drip not less than 25 mm from the wall surface.

9.20.14. Protection during Work

9.20.14.1. Laying Temperature of Mortar and Masonry
1) Intent StatementMortar and masonry shall be maintained at a temperature not below 5°C during installation and for not less than 48 h after installation.
2) Intent StatementNo frozen material shall be used in mortar mix.
9.20.14.2. Protection from Weather
1) Intent StatementThe top surface of uncompleted masonry exposed to the weather shall be completely covered with a waterproofing material when construction is not in progress.

9.20.15. Reinforcement for Earthquake Resistance

9.20.15.1. Amount of Reinforcement
1) Intent StatementWhere reinforcement is required in this Section, masonry walls shall be reinforced horizontally and vertically with steel having a total cross-sectional area of not less than 0.002 times the horizontal cross-sectional area of the wall, so that not less than one-third of the required steel area is installed either horizontally or vertically and the remainder in the other direction.
9.20.15.2. Installation Standard
1) Intent StatementWhere reinforcement for masonry is required in this Section, it shall be installed in conformance with the requirements for reinforced masonry as contained in CAN/CSA-A371, “Masonry Construction for Buildings.”

9.20.16. Corrosion Resistance

9.20.16.1. Corrosion Resistance of Connectors
1) Intent StatementCarbon steel connectors required to be corrosion-resistant shall be galvanized to at least the minimum standards in Table 9.20.16.1.
Table 9.20.16.1.
Minimum Requirements for Galvanizing
Forming part of Sentence 9.20.16.1.(1)
Connector Material ASTM Standard Coating Class or Thickness
Wire ties and continuous reinforcing (hot-dipped galvanizing)

A 153/A 153M

Class B2 or 458 g/m2
Hardware and bolts

A 153/A 153M

See A 153/A 153M

Strip, plate, bars and rolled sections (not less than 3.18 mm thick)

A 123/A 123M

610 g/m2

Sheet (less than 3.18 mm thick)

A 123/A 123M

305 g/m2 on material 0.76 mm thick(1)
Notes to Table 9.20.16.1.:
(1) ASTM A 123/A 123M does not apply to metal less than 3.18 mm thick. Galvanizing coatings may be interpolated for thicknesses between 3.18 mm and 0.76 mm.

9.20.17. Above-Ground Flat Insulating Concrete Form Walls

9.20.17.1. Thickness of Flat Insulating Concrete Form Walls
1) Intent StatementThe thickness of the concrete in flat insulating concrete form walls not in contact with the ground shall be
a) not less than 140 mm, and
b) constant for the entire height of the wall.
9.20.17.2. Reinforcement for Flat Insulating Concrete Form Walls
1) Intent StatementHorizontal reinforcement in above-grade flat insulating concrete form 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 at 600 mm o.c., and
b) be placed in the middle third of the wall section.
2) Intent StatementVertical reinforcement in above-grade flat insulating concrete form walls shall
a) consist of 10M bars at 400 mm o.c., and
b) be placed in the middle third of the wall section.
3) Intent StatementVertical reinforcement required by Sentence (2) and interrupted by wall openings shall be placed not more than 600 mm from each side of the opening.
9.20.17.3. Openings in Non-Loadbearing Flat Insulating Concrete Form Walls
1) Intent StatementNo openings shall occur within 1 200 mm of interior and exterior corners of exterior non-loadbearing flat insulating concrete form walls.
2) Intent StatementPortions of walls above openings in non-loadbearing flat insulating concrete form walls shall have a minimum depth of concrete of no less than 200 mm across the width of the opening.
3) Intent StatementOpenings that are more than 600 mm but not more than 3 000 mm in width in non-loadbearing flat insulating concrete form walls shall be reinforced at the top and bottom with one 10M bar.
4) Intent StatementOpenings more than 3 000 mm in width in non-loadbearing flat insulating concrete form walls shall be reinforced on all four sides with two 10M bars.
5) Intent StatementReinforcing bars described in Sentences (3) and (4) shall extend 600 mm beyond the edges of the opening.
6) Intent StatementThe cumulative width of openings in non-loadbearing flat insulating concrete form walls shall not make up more than 70% of the length of any wall.
9.20.17.4. Openings in Loadbearing Flat Insulating Concrete Form Walls
1) Intent Statementchange beginNo openings shall occur within 1 200 mm of interior and exterior corners of exterior loadbearing flat insulating concrete form walls.change end
2) Intent StatementIn loadbearing flat insulating concrete form walls, lintels shall be provided over all openings wider than 900 mm.
3) Intent StatementLintels described in Sentence (2) shall be constructed in accordance with Tables A-17, A-18 or A-19
4) Intent StatementLintels described in Sentence (2) over openings wider than 1 200 mm shall be reinforced for shear with 10M stirrups at a maximum spacing of half the distance from the bottom reinforcing bar to the top of the lintel.
9.20.17.5. Framing Supported on Flat Insulating Concrete Form Walls
1) Intent StatementFloor joists supported on the side of flat insulating concrete form walls shall be supported with joist hangers secured to wood ledger boards.
2) Intent StatementThe ledger boards referred to in Sentence (1) shall be not less than
a) 38 mm thick, and
b) the depth of the floor joists.
3) Intent StatementAnchor bolts shall be used to secure ledger boards to flat insulating concrete form walls and shall be
a) embedded in the wall to a depth not less than 100 mm, and
b) spaced in accordance with Table 9.20.17.5.
4) Intent StatementFloor joists and building frames supported on the top of flat insulating concrete form walls shall be anchored in conformance with Article 9.23.6.1.
Table 9.20.17.5.
Maximum Anchor Bolt Spacing for the Connection of Floor Ledgers to Flat Insulating Concrete Form Walls
Forming part of Sentence 9.20.17.5.(3)
Maximum Clear Floor Span, m Maximum Anchor Bolt Spacing, mm
Staggered 12.7 mm Diameter Anchor Bolts Staggered 16 mm Diameter Anchor Bolts
2.44 450 500
3.0 400 450
4.0 300 400
5.0 275 325
9.20.17.6. Anchoring of Roof Framing to the Top of Flat Insulating Concrete Form Walls
1) Intent StatementRoof framing supported on the top of flat insulating concrete form walls shall be fixed to the top plates, which shall be anchored to the wall with anchor bolts
a) not less than 12.7 mm in diameter, and
b) spaced at not more than 1 200 mm o.c.
2) Intent StatementThe anchor bolts described in Sentence (1) shall be placed in the centre of the flat insulating concrete form wall and shall be embedded no less than 100 mm into the concrete.
3) Intent StatementAttachment of roof framing to wood top plates shall be in accordance with Table 9.23.3.4.
9.20.17.7. Protection from Precipitation and Damage
1) Intent StatementAbove-ground flat insulating concrete form walls shall be protected from precipitation and damage in conformance with Section 9.27.