9.27.

(1) Where lumber, wood shingles, shakes, fibre-cement shingles, planks and sheets, plywood, OSB, waferboard, hardboard, vinyl, aluminum and steel, including trim and soffits, are installed as cladding on wood-frame walls exposed to precipitation, the cladding assembly shall comply with,

(a) Subsections 9.27.2. to 9.27.13., or

(b) Part 5.

(2) Where stucco is installed as cladding on wood-frame or masonry walls exposed to precipitation, the cladding assembly shall comply with,

(a) Subsections 9.27.2. to 9.27.4., and Section 9.28., or

(b) Part 5.

(3) Where masonry serves as cladding on wood-frame or masonry walls exposed to precipitation, the cladding assembly shall comply with,

(a) Subsections 9.27.2. to 9.27.4., and Section 9.20., or

(b) Part 5.

(4) Where asphalt shingles are installed as cladding on wood-frame walls exposed to precipitation, the cladding assembly shall comply with,

(a) Subsections 9.26.7. and 9.27.2. to 9.27.4., or

(b) Part 5.

(5) Where cladding materials other than those described in Sentences (1) to (4) are installed, or where these are installed on substrates other than those identified in Sentences (1) to (4), the materials and installation shall comply with Part 5.

(1) Except where exterior walls are protected from precipitation or where it can be shown that ingress will not adversely affect occupant health or safety, exterior walls shall be designed and constructed to,

(a) minimize the ingress of precipitation into the assembly, and

(b) prevent ingress into interior space.

(2) Except where exterior walls are protected from specific mechanisms of deterioration, such as mechanical impact and ultraviolet radiation, exterior walls shall be designed and constructed to minimize the likelihood of their required performance being reduced to an unacceptable level as a result of those mechanisms.

(1) Exterior walls exposed to precipitation shall be protected against ingress of precipitation with an exterior cladding assembly consisting of a first plane of protection and a second plane of protection where the wall encloses spaces of residential occupancy or spaces that directly serve spaces of residential occupancy.

(1) Where walls required to provide protection from precipitation comprise assemblies with first and second planes of protection,

(a) the first plane of protection shall,

(i) consist of cladding, with appropriate trim, accessory pieces and fasteners, and

(ii) be designed and constructed to minimize the passage of rain and snow into the wall by minimizing holes and managing precipitation ingress caused by kinetic energy of raindrops, surface tension, capillarity, gravity, and air pressure differences,

(b) the second plane of protection shall be designed and constructed to,

(i) intercept all precipitation that gets past the first plane of protection, and

(ii) effectively dissipate any precipitation to the exterior, and

(c) the protection provided by the first and second planes of protection shall be maintained at,

(i) wall penetrations created by the installation of components and services such as windows, doors, ventilation ducts, piping, wiring and electrical outlets, and

(ii) the interface with other wall assemblies.

(1) A clearance of not less than 200 mm shall be provided between finished ground and cladding that is adversely affected by moisture, such as untreated wood, plywood, OSB, waferboard and hardboard.

(2) A clearance of not less than 50 mm shall be provided between a roof surface and cladding that is adversely affected by moisture, such as untreated wood, plywood, OSB, waferboard and hardboard.

(1) The second plane of protection shall consist of a drainage plane with appropriate inner boundary and flashing to dissipate rainwater to the exterior.

(2) The inner boundary of the drainage plane shall comply with Articles 9.27.3.2.v1 to 9.27.3.6.

(3) The protection provided by the second plane of protection shall be maintained,

(a) at wall penetrations created by the installation of components and services such as windows, doors, ventilation ducts, piping, wiring and electrical outlets, and

(b) at the interface with other wall assemblies.

(4) Flashing material and installation shall comply with Articles 9.27.3.7. and 9.27.3.8.

(1) Sheathing membranes shall conform to the performance requirements of CAN/CBSB-51.32-M, “Sheathing, Membrane, Breather Type”.

(1) Except as provided in Articles 9.27.3.4. to 9.27.3.6., at least one layer of sheathing membrane shall be applied beneath siding, stucco or masonry veneer.

(2) Sheathing membrane required in Sentence (1) shall be applied so that joints are lapped not less than 100 mm.

(3) Where sheathing membrane required in Sentence (1) is applied horizontally, the upper sheets shall overlap the lower sheets.

(1) Where non-wood-based rigid exterior insulating sheathing, or exterior insulating sheathing with an integral sheathing membrane is installed, a separate sheathing membrane is not required.

(2) Where insulating sheathing is installed as provided in Sentence (1),

(a) sheathing panels subject to moisture deterioration shall be sealed at all joints, and

(b) the joints of sheathing panels not subject to moisture deterioration shall be,

(i) sealed at all joints, or

(ii) lapped or tongue and groove, and detailed to ensure drainage of water to the exterior.

(1) Except as provided in Article 9.27.3.6., where no sheathing is used, at least 2 layers of sheathing membrane shall be applied beneath the cladding.

(2) All joints in the sheathing membrane required in Sentence (1) shall occur over framing, and the membrane shall be fastened to the framing with roofing nails or staples spaced not more than 150 mm along the edges of the outer layer of sheathing paper.

(3) Wall sheathing is permitted to be used in lieu of 1 layer of sheathing membrane required in Sentence (1), and the thickness need not conform to Table 9.23.16.2.A.v1

(1) Sheathing membrane is permitted to be omitted beneath cladding when the joints in the cladding are formed to effectively prevent the passage of wind and rain in conformance with Sentence (2) or (3), as applicable.

(2) Cladding consisting of sheets of plywood, hardboard, OSB, waferboard or fibre cement is considered to meet the requirements of Sentence (1), provided the cladding is applied so that

(a) all edges are directly supported by framing, and

(b) the vertical joints between adjacent sheets are sealed and,

(i) covered with battens,

(ii) shiplapped, or

(iii) otherwise matched to provide weathertight joints, and

(c) the horizontal joints between adjacent sheets are sealed and,

(i) shiplapped, or

(ii) otherwise matched to provide weathertight joints.

(3) Metal siding consisting of sheets of metal is considered to meet the requirements of Sentence (1) where the joints between sheets are of the locked-seam type.

(1) Flashing shall consist of not less than,

(a) 1.73 mm thick sheet lead,

(b) 0.33 mm thick galvanized steel,

(c) 0.46 mm thick copper,

(d) 0.46 mm thick zinc,

(e) 0.48 mm thick aluminum, or

(f) 1.02 mm thick vinyl.

(1) Except as provided in Sentence (2), flashing shall be installed at,

(a) every horizontal junction between claddings elements,

(b) every horizontal offset in the cladding, and

(c) every horizontal line where the cladding substrates change and where,

(i) the substrates differ sufficiently for stresses to be concentrated along that line, or

(ii) the installation of the cladding on the lower substrate may compromise the drainage of moisture from behind the cladding above.

(2) Flashing need not be installed as described in Sentence (1),

(a) where the upper cladding elements overlap the lower cladding elements by not less than 25 mm,

(b) where,

(i) the cladding above and below the joint is installed outboard of a drained and vented air space, and

(ii) the horizontal detail is constructed so as to minimize ingress of precipitation into the air space, or

(c) at horizontal construction joints in stucco, where,

(i) the joint is finished with an expansion-contraction strip, and

(ii) the cladding is installed outboard of a drained and vented air space.

(3) Except as provided in Sentence (6), flashing shall be installed over exterior wall openings where the vertical distance from the bottom of the eave to the top of the trim is more than one-quarter of the horizontal overhang of the eave.

(4) Flashing described in Sentences (1) and (3) shall,

(a) extend not less that 50 mm upward inboard of the sheathing membrane or sheathing installed in lieu of the sheathing membrane,

(b) have a slope of not less than 6% toward the exterior after the expected shrinkage of the building frame,

(c) terminate at each end with an end-dam,

(i) with a height in millimetres not less than 25 mm or 1/10 of the value of the 1 in 5 driving rain wind pressure in Pa, and

(ii) at the height defined in Subclause (c)(i), extending to the face of the adjacent cladding,

(d) lap not less than 10 mm vertically over the building element below, and

(e) terminate in a drip extending not less than 5 mm outward from the outer face of the building element below.

(5) Except as provided in Sentence (6), where the sills of windows and doors installed in exterior walls are not self-flashing, flashing shall be installed between the underside of the window or door and the wall construction below.

(6) Where a window or exterior door is provided with an integral exterior flange and is designed to be installed on the exterior of essentially flat lock-seam metal cladding without a head or sill flashing, the flange shall be,

(a) bedded into a non-hardening sealant material, and

(b) screwed down over the sealant through to the wall framing to form a waterproof joint.

(1) Caulking shall be provided where required to prevent the entry of water into the structure.

(2) Caulking shall be provided between masonry, siding or stucco and the adjacent door and window frames or trim, including sills unless such locations are completely protected from the entry of rain.

(3) Caulking shall be provided at vertical joints between different cladding materials unless the joint is suitably lapped or flashed to prevent the entry of rain.

(1) Caulking shall be,

(a) a non-hardening type suitable for exterior use,

(b) selected for its ability to resist the effects of weathering, and

(c) compatible with and adhere to the substrate to which it is applied.

(2) Caulking shall conform to,

(a) CGSB 19-GP-5M, “Sealing Compound, One Component, Acrylic Base, Solvent Curing”,

(b) CAN/CGSB-19.13-M, “Sealing Compound, One Component, Elastomeric, Chemical Curing”,

(c) CGSB 19-GP-14M, “Sealing Compound, One Component, Butyl-Polyisobutylene Polymer Base, Solvent Curing”, or

(d) CAN/CGSB-19.24-M, “Multicomponent, Chemical Curing Sealing Compound”.

(1) Except as permitted in Sentences (2) to (7), cladding shall be fastened to the framing members or furring members, or to blocking between the framing members.

(2) Vertical lumber and stucco lath or reinforcing are permitted to be attached to sheathing only where the sheathing consists of not less than,

(a) 14.3 mm lumber,

(b) 12.5 mm plywood, or

(c) 12.5 mm OSB or waferboard.

(3) Vertically applied metal siding and wood shingles and shakes are permitted to be attached to the sheathing only where the sheathing consists of not less than,

(a) 14.3 mm lumber,

(b) 7.5 mm plywood, or

(c) 7.5 mm OSB or waferboard.

(4) Asbestos-cement shingles are permitted to be attached to the sheathing only when the sheathing consists of not less than,

(a) 14.3 mm lumber,

(b) 9.5 mm plywood, or

(c) 9.5 mm OSB or waferboard.

(5) Where wood shingles or shakes are applied to sheathing that is not suitable for attaching the shingles or shakes, the shingles or shakes may be attached to a wood lath not less than 38 mm by 9.5 mm thick securely nailed to the framing and applied as described in Article 9.27.7.5.

(6) Where asbestos-cement shingles are applied to sheathing that is not suitable for attaching the shingles, the shingles may be fastened to a wood lath not less than 89 mm by 9.5 mm thick securely nailed to the framing.

(7) Lath referred to in Sentence (6) shall be applied so that it overlaps the preceding shingle course by not less than 20 mm.

(1) Blocking for the attachment of cladding shall be not less than 38 mm by 38 mm lumber securely nailed to the framing and spaced not more than 600 mm o.c.

(1) Except as permitted in Sentences 9.27.5.1.(5) and (6), furring for the attachment of cladding shall be not less than 19 mm by 38 mm lumber when applied over sheathing.

(2) When applied without sheathing, furring referred to in Sentence (1) shall be not less than,

(a) 19 mm by 64 mm lumber on supports spaced not more than 400 mm o.c., or

(b) 19 mm by 89 mm on supports spaced not more than 600 mm o.c.

(3) Furring referred to in Sentence (1) shall be,

(a) securely fastened to the framing, and

(b) spaced not more than 600 mm o.c.

(1) Nail or staple size and spacing for the attachment of cladding and trim shall conform to Table 9.27.5.4.

(1) Nails or staples for the attachment of cladding and wood trim shall be corrosion-resistant and shall be compatible with the cladding material.

(1) Fasteners for metal or vinyl cladding shall be positioned to permit expansion and contraction of the cladding.

(1) Fasteners for shakes and shingles shall penetrate through the nail-holding base or not less than 19 mm into the framing.

(2) Fasteners for cladding other than that described in Sentence (1) shall penetrate through the nail-holding base or not less than 25 mm into the framing.

(1) Lumber siding shall be sound, free of knot holes, loose knots, through checks or splits.

(1) Drop, rustic, novelty, lapped board and vertical wood siding shall be not less than 14.3 mm thick and not more than 286 mm wide.

(2) Bevel siding shall be,

(a) not less than 5 mm thick at the top, and

(b) not less than,

(i) 12 mm thick at the butt for sidings 184 mm or less in width, and

(ii) 14.3 mm thick at the butt for sidings wider than 184 mm.

(3) Bevel siding shall be not more than 286 mm wide.

(1) Lumber siding shall prevent water from entering at the joints by the use of lapped or matched joints or by vertical wood battens.

(2) Siding shall overlap not less than 1 mm per 16 mm width of lumber, but not less than,

(a) 9.5 mm for matched siding,

(b) 25 mm for lapped bevel siding, or

(c) 12 mm for vertical battens.

(1) Shingles and shakes shall conform to,

(a) CSA O118.1, “Western Cedars Shakes and Shingles”, or

(b) CSA O118.2-M, “Eastern White Cedar Shingles”.

(2) Western cedar shakes shall be not less than No. 1 grade or Handsplit grade, and western cedar shingles not less than No. 2 grade, except that No. 3 grade may be used for undercoursing.

(3) Eastern white cedar shakes shall be at least B (clear) grade, except that C grade may be used for undercoursing.

(1) Shingles and shakes shall be not less than 65 mm or more than 350 mm wide.

(1) Shingles or shakes shall be fastened with nails located approximately 20 mm from each edge and not less than 25 mm above the exposure line for single-course applications, or approximately 50 mm above the butt for double-course applications.

(1) In single-course application, joints in succeeding courses shall be offset at least 40 mm so that joints in any 2 of 3 consecutive courses are staggered.

(2) In double-course application, joints in the outer course shall be offset from joints in the under-course by not less than 40 mm, and joints in succeeding courses shall be offset not less than 40 mm.

(1) When lath is used with double-course application (see Sentence 9.27.5.1.(5)), it shall be spaced according to the exposure and securely fastened to the framing.

(2) The butts of the under-course of the application referred to in Sentence (1) shall rest on the top edge of the lath.

(3) The outer course of the application referred to in Sentence (1) shall be fastened to the lath with nails of sufficient length to penetrate through the lath.

(4) The butts of the shingles or shakes shall be so located that they project not less than 12 mm below the bottom edge of the lath referred to in Sentence (1).

(5) If wood lath is not used, the butts of the under-course shingles or shakes of the application referred to in Sentence (1) shall be located 12 mm above the butts of the outer course.

(1) The exposure and butt thickness of shingles and shakes shall conform to Table 9.27.7.6.

(1) Asbestos-cement shingles and sheets shall conform to,

(a) CAN/CGSB-34.4-M, “Siding, Asbestos-Cement, Shingles and Clapboards”,

(b) CAN/CGSB-34.5-M, “Sheets, Asbestos-Cement, Corrugated”,

(c) CAN/CGSB-34.14-M, “Sheets, Asbestos-Cement, Decorative”,

(d) CAN/CGSB-34.16, “Sheets, Asbestos-Cement, Flat, Fully Compressed”,

(e) CAN/CGSB-34.17-M, “Sheets, Asbestos-Cement, Flat, Semicompressed”, or

(f) CAN/CGSB-34.21-M, “Panels, Sandwich Asbestos-Cement with Insulating Cores”.

(1) Asbestos-cement shingles shall weigh not less than 8.06 kg/m².

(2) Asbestos-cement sheet shall be not less than,

(a) 4.75 mm thick where applied to studs spaced not more than 400 mm o.c., and,

(b) 6 mm thick where applied to studs spaced not more than 600 mm o.c.

(3) Where applied over sheathing, the thickness of asbestos-cement sheet shall be not less than 3.15 mm.

(1) Asbestos-cement shingles shall be fastened with nails located not less than 25 mm above the exposure line.

(1) Asbestos-cement shingles shall be installed so that vertical joints in succeeding courses are staggered.

(2) Asphalt-coated backer strips shall be installed behind each vertical joint.

(3) Shingles referred to in Sentence (1) shall have not less than a 25 mm head lap.

(1) Vertical joints of asbestos-cement panels shall be protected with batten strips, caulking or other suitable method.

(2) Horizontal joints of asbestos-cement panels shall be lapped, flashed, caulked or otherwise suitably protected.

(1) Plywood cladding shall be exterior type conforming to,

(a) CSA O115-M, “Hardwood and Decorative Plywood”,

(b) CSA O121-M, “Douglas Fir Plywood”,

(c) CSA O151, “Canadian Softwood Plywood”, or

(d) CSA O153-M, “Poplar Plywood”.

(1) Plywood cladding shall be not less than 6 mm thick when applied directly to sheathing.

(2) When applied directly to framing or over furring strips, plywood cladding thickness shall conform to Table 9.27.9.2.

(3) The thickness of grooved or textured plywood shall be measured at the point of least thickness.

(1) The edges of plywood cladding shall be treated with a suitable paint or sealer.

(1) Plywood applied in panels shall have all edges supported.

(2) Not less than a 2 mm gap shall be provided between panels referred to in Sentence (1).

(3) Vertical joints in cladding referred to in Sentence (1) shall be protected with batten strips or caulking when the plywood joints are not matched.

(4) Horizontal joints in cladding referred to in Sentence (1) shall be lapped not less than 25 mm or shall be suitably flashed.

(1) Plywood applied in horizontal lapped strips shall have not less than a 2 mm gap provided at the butted ends, which shall be caulked.

(2) The horizontal joints of siding described in Sentence (1) shall be lapped not less than 25 mm.

(3) Wedges shall be inserted under all vertical butt joints and at all corners when horizontal lapped plywood is applied without sheathing.

(1) Factory-finished hardboard cladding shall conform to CAN/CGSB-11.5M, “Hardboard, Precoated, Factory-Finished, for Exterior Cladding”.

(2) Hardboard cladding that is not factory finished shall conform to Types 1, 2 or 5 in CAN/CGSB-11.3-M, “Hardboard”.

(1) Type 1 or 2 hardboard cladding shall be not less than,

(a) 6.0 mm thick when applied over sheathing that provides continuous support, and

(b) 7.5 mm thick when applied to furring or framing members not more than 400 mm o.c.

(2) Type 5 hardboard cladding shall be not less than 9.0 mm thick when applied over sheathing that provides continuous support or over furring or framing members spaced not more than 400 mm o.c.

(3) Where hardboard cladding is grooved, the grooves shall not extend more than 1.5 mm into the minimum required thickness.

(1) Hardboard cladding applied in panels shall have all edges supported with not less than a 5 mm gap provided between sheets.

(2) Vertical joints in cladding described in Sentence (1) shall be protected with batten strips or caulking when the joints are not matched.

(3) Horizontal joints in cladding described in Sentence (1) shall be lapped not less than 25 mm or shall be suitably flashed.

(1) Hardboard applied in horizontal lapped strips shall have not less than a 5 mm gap provided at the butted ends, which shall be caulked or otherwise protected with suitable mouldings.

(2) The horizontal joints of siding described in Sentence (1) shall overlap not less than 1 mm per 16 mm width of siding board but not less than 9.5 mm for matched joint siding or 25 mm for lapped siding.

(1) Not less than 3 mm clearance shall be provided between hardboard siding and door or window frames.

(1) OSB and waferboard cladding shall conform to CSA O437.0, “OSB and Waferboard”.

(1) OSB conforming to O-2 grade shall be not less than 6.0 mm thick where applied directly to sheathing.

(2) OSB conforming to O-2 grade applied directly to framing or over furring strips, shall conform to the thickness shown for plywood in Table 9.27.9.2.

(3) OSB conforming to O-1 grade and waferboard conforming to R-1 grade shall be not less than 7.9 mm thick where applied directly to sheathing.

(4) Where applied directly to framing or over furring strips, OSB conforming to O-1 grade and waferboard conforming to R-1 grade shall be not less than,

(a) 9.5 mm thick on supports spaced not more than 400 mm o.c., and

(b) 12.7 mm thick on supports spaced not more than 600 mm o.c.

(1) OSB and waferboard applied in panels shall have all edges supported and treated with a primer or sealer.

(2) Not less than a 3 mm gap shall be provided between sheets in cladding described in Sentence (1).

(3) Vertical joints in cladding described in Sentence (1) shall be protected with batten strips or caulking when the OSB and waferboard joints are not matched.

(4) Horizontal joints in cladding described in Sentence (1) shall be lapped not less than 25 mm or shall be suitably flashed.

(1) At least a 3 mm clearance shall be provided between OSB and waferboard cladding and door or window frames.

(1) Horizontal and vertical strip steel siding, including flashing and trim accessories, shall conform to CAN/CGSB-93.4, “Galvanized Steel and Aluminum-Zinc Alloy Coated Steel Siding, Soffits and Fascia, Prefinished, Residential”.

(2) Steel sheet cladding shall have a minimum thickness of 0.3 mm and conform to CAN/CGSB-93.3-M, “Prefinished Galvanized and Aluminum-Zinc Alloy Steel Sheet for Residential Use”.

(3) Horizontal and vertical strip aluminum siding, including flashing and trim accessories, shall conform to CAN/CGSB-93.2-M, “Prefinished Aluminum Siding, Soffits and Fascia, for Residential Use”.

(4) Aluminum sheet cladding shall conform to CAN/CGSB-93.1-M, “Sheet, Aluminum Alloy, Prefinished, Residential” and shall have a thickness of not less than 0.58 mm, except that siding supported by backing or sheathing shall have a thickness of not less than 0.46 mm.

(1) Vinyl siding, including flashing and trim accessories, shall conform to CAN/CGSB-41.24, “Rigid Vinyl Siding, Soffits and Fascia”.

(1) The attachment of vinyl siding shall conform to the requirements in Subsection 9.27.5. for metal siding.