Information on design wind speeds for particular areas may be available from the appropriate authority. Also see the table associated with the definition of ‘design wind speed’ for wind classes. A map indicating wind regions of Australia is contained in Part 2.2.
Explanatory information: Other relevant roof tile requirements
In addition to the requirements of this Part, requirements for roof tiles also exist in NCC Volume Two and other Parts of the ABCB Housing Provisions. They include the following:
For the sizing and fixing of roof battens - NCC Volume Two H1D6(3) (steel battens) and H1D6(4) (timber battens).
Figure 7.3.2d Fixing of ridge capping — ridge clip fixing
Figure 7.3.2e Fixing of hip capping — clout or screw fixing
Explanatory information
For the purposes of Figures 7.3.2a, 7.3.2b and 7.3.2c, ‘edge of roof’ is a 1.2 m wide band bounded by the eaves, hips and barge measured toward the ‘ridge of roof’.
follow the roof line, allowing not less than 75 mm upturn to the wall and a minimum of 150 mm in width and moulded into the tiles; and
have a horizontal overflashing, stepped overflashing or raked overflashing built into the masonry leaf or veneer, except that one continuous flashing may be used as both an apron flashing or an overflashing; and
have joints overlap the one below by not less than 75 mm in the direction of flow.
For flashing where the upturn can be fixed to or behind the supporting frame or cladding, it must—
follow the roof line, allowing not less than 75 mm upturn to the wall and a minimum of 150 mm in width and moulded into the tiles; and
be fastened into or behind the wall cladding at each end and at a maximum of 600 mm centres; and
have joints overlap the one below by not less than 75 mm in the direction of flow.
be either collar, apron or other purpose made flashings; and
have a minimum upturn on the penetration of not less than 75 mm and a minimum of 150 mm in width surrounding the penetration and be moulded into the tiles; and
permit the total drainage of the area above the penetration.
(4) Joints in flashing must be not less than 75 mm and lapped in the direction of fall of the roof.
(5) Fixings for flashings must be compatible with the flashing material.
(6) Lead flashings must not be used on any roof that is part of a drinking water catchment area.
sarking fixed to supporting members at not more than 300 mm centres; and
no sags more than 40 mm in the sarking.
Table 7.3.4 Sarking requirements for tiled roofs
Roof pitch
Maximum rafter/truss top chord length without sarking (mm) Note 1
<18°
N/A Note 2
≥18° <20°
4 500
≥20° <22°
5 500
≥22°
6 000
Table Notes
The maximum rafter/truss top chord length is measured from the topmost point of the rafter/truss i.e. the apex downwards. Where the maximum length is exceeded, sarking must be installed over the remainder of the rafter/truss top chord length towards the eave line of the roof, or equivalent where the building has no eaves.
All tiled roofs with a pitch less than 18 degrees must be provided with sarking, regardless of rafter/truss chord length.
(1) An anti-ponding device/board must be provided where sarking is installed on—
roofs with a pitch less than 20°; and
roofs with no eaves overhang, regardless of the roof pitch.
(2) An anti-ponding device required by (1) must be water resistant and fixed along the eaves line from the top of the fascia back up the rafter with a clearance of approximately 50 mm below the first batten (See Figure 7.3.5).
Figure 7.3.5 Typical installation of anti-ponding device/board
Where an eaves gutter is provided in accordance with H2D6(1), tiles must overhang the fascia or tiling batten by not less than 35 mm (See Figure 7.3.5).