Part 5.7 Weatherproofing of masonry
New for 2022
- less than 25 mm wide; and
- more than 75 mm wide.
The 25 mm clear width of the cavity needs to be maintained regardless of any wall membranes, sheet bracing or services installed to the supporting frame.
Where mullions are located within a cavity, a vertical damp-proof course must be placed between the outer masonry leaf and the mullion to prevent moisture penetration.
Damp-proof courses and flashings – material
Damp-proof courses and flashings must consist of—
- a material that complies with AS/NZS 2904; or
- embossed black polyethylene film of high impact resistance and low slip, with a nominal thickness of 0.5 mm prior to embossing, and comply with clause 7.6 of AS/NZS 2904; or
- polyethylene coated metal, that has an aluminium core of not less than 0.1 mm thick, is coated both sides with bitumen adhesive enclosed in polyethylene film of not less than 0.1 mm thick on each face, and has a nominal total thickness of not less than 0.5 mm prior to embossing; or
- bitumen impregnated materials of not less than 2.5 mm thick, that comply with clause 7.5 of AS/NZS 2904; or
- termite sheet materials complying with Part 3.4 (with no penetrations) serving the purpose of a damp-proof course and/or flashing that is continuous through the wall or pier.
Damp-proof courses and flashings – installation
- located so as to form a continuous damp-proofing barrier—
- around the bottom perimeter of walls where constructed on a concrete slab; and
- in walls and piers below suspended floors; and
- where a masonry wall passes through a roof; and
- where a roof abuts an external masonry wall; and
- to the bottom and tops of windows and doors and the like in accordance with (3), except a damp-proof course or a flashing need not be provided to the top of a window or door where the opening is protected by an eave of a width more than 3 times the height of the masonry veneer above the opening; and
- continuous through the wall or pier and be visible from the outside face of the wall.
- 150 mm above the adjacent ground level; or
- 75 mm above the finished surface level of adjacent paved, concreted or landscaped areas that slope away from the wall; or
- 50 mm above finished paved, concreted or landscaped areas complying with 3.3.3(b)(ii) and protected from the direct effects of the weather by a carport, verandah or the like; or
- in low rainfall intensity areas—
- 15 mm above finished paved, concreted or landscaped areas; or
- 0 mm above finished paved, concreted or landscaped areas if the damp-proof course is protected from the direct effects of the weather by a carport, verandah or the like.
- installed so that the flashing extends not less than 150 mm beyond the reveals on each side of the opening; and
- located not more than—
- one course below the sill brick course; and
- 300 mm above the opening; and
- turned up in the cavity not less than 150 mm above the opening; and
- embedded not less than 30 mm into—
- for masonry veneer, the masonry leaf; and
- for cavity masonry, the outer masonry leaf; and
- attached to the window or wall framing.
- a minimum of 50 mm in height, by the width of the vertical mortar joint; and
- at not more than 1.2 m centres; and
Weatherproofing for single leaf masonry walls
New for 2022
- The coating must extend from the uppermost exposed part of the wall—
- to a level adjacent to the internal finished floor level, if the external masonry wall leaf overhangs the edge of the slab by not less than 10 mm; or
- 50 mm below the internal floor level if no edge overhang is provided.
- Acceptable external waterproof finishes are—
- three coats of 100% acrylic based exterior quality gloss paint; or
- one complete coat of cement based paint and two coats of 100% acrylic based exterior quality gloss paint; or
- clear water repellent, provided the wall is protected by a roof overhang of not less than 1500 mm.