9.20.9.

(1) Vertical joints in adjacent masonry courses shall be offset unless each wythe of masonry is reinforced with the equivalent of no fewer than 2 corrosion-resistant steel bars of 3.76 mm diam placed in the horizontal joints at vertical intervals not exceeding 460 mm.

(2) Where joints in the reinforcing referred to in Sentence (1) occur, the bars shall be lapped not less than 150 mm.

(1) Except as provided in Article 9.20.9.5 for 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 Articles 9.20.9.4.

(1) Where wythes are bonded together with masonry units, the bonding units shall comprise not less than 4 per cent of the wall surface area.

(2) Bonding 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) Units described in Sentence (1) shall extend not less than 90 mm into adjacent wythes.

(1) Where 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) Other 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) Metal 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) Metal 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) Where 2 or more wythes in walls other than cavity walls and masonry veneer/masonry back-up walls are tied together with metal ties of the individual rod type, the space between wythes shall be completely filled with mortar.

(6) Ties 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) Except 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) Within 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) Within 300 mm of any openings, the ties described in Sentence (7) shall be spaced not more than 900 mm apart.

(1) Masonry veneer 70 mm or more in thickness and resting on a bearing support shall be tied to masonry back-up 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.

(2) The straps described in Sentence (1) that are fastened to the 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 30 mm.

(3) Masonry veneer individually supported by masonry or wood-frame back-up shall be secured to the back-up in conformance with Subsection 4.3.2.

(4) The straps described in Sentence (1) may be installed against one of the sheathings listed in Table 9.23.16.2.A.v1 provided that,

(a) the tie is in contact with the exterior surface of the sheathing, and

(b) the sheathing beneath the tie is not compressed.

(1) Glass block shall have horizontal joint reinforcement of 2 corrosion-resistant bars of not less than 3.76 mm or expanded metal strips not less than 75 mm wide,

(a) spaced at vertical intervals of not more than 600 mm for units 190 mm or less in height, and

(b) installed in every horizontal joint for units higher than 190 mm.

(2) Reinforcement required in Sentence (1) shall be lapped not less than 150 mm.