NCC 2019 Volume Two
Part 3.5.2 Roof tiles and shingles

Part 3.5.2 Roof tiles and shingles

Appropriate Performance Requirements

Appropriate Performance Requirements

Where an alternative roof cladding is proposed as a Performance Solution to that described in Part 3.5.1, that proposal must comply with—

  1. Performance RequirementP2.1.1; and
  2. Performance RequirementP2.2.2; and
  3. the relevant Performance Requirements determined in accordance with A2.2(3) and A2.4(3) as applicable.

Acceptable Construction Manuals

3.5.2.0 Application

Performance RequirementsP2.1.1 and P2.2.2 are satisfied for roof cladding if it complies with one or a combination of the following:

(a)

Roof tiling: AS 2050.

(b)

Terracotta, fibre-cement and timber slates and shingles: AS 4597.

Acceptable Construction Practice

3.5.2.1 Application

Compliance with this acceptable construction practice satisfies Performance Requirements P2.1.1 and P2.2.2 for roof tiles, provided—

(a)

the building is located in an area with a design wind speed of not more than N3; and

(b)

the roof tiles comply with AS 2049; and

(c)

the roof has a pitch of not less than 15 degrees and not more than 35 degrees, and

(d)

the roof tiles are installed in accordance with the provisions of this Part.

Explanatory information:

Explanatory information:
  1. Design wind speeds:

    Information on design wind speed for particular areas may be available from the appropriate authority. Also see Table 3 for wind classes. A map indicating wind regions of Australia is contained in Part 3.0.

  2. Other relevant roof tile requirements:

    A number of other Parts of Volume Two contain specific requirements relevant to roof tiles, in addition to the provisions of this Part. They include—

    1. for the sizing and fixing of roof battens—
      1. Part 3.4.2 for steel battens; and
      2. Part 3.4.3 for timber battens; and
    2. Part 3.7.3 for roofing over a separating wall; and
    3. Part 3.5.3 for gutters and downpipes.

3.5.2.2 Fixing of roof tiles and ancillaries

(a)

Roof tiles and hip, ridge, barge and capping tiles must be fixed in accordance with Table 3.5.2.1 and Figures 3.5.2.1 and 3.5.2.2.

(b)

Fixing required by Table 3.5.2.1 must consist of one or a combination of the following:

(i)

Galvanized clout nails with a minimum diameter of 2.8 mm and of a length so that the nail will penetrate not less than 15 mm into the batten.

(ii)

Self embedding head screws of 8-18 gauge and of a length so that the screw will penetrate not less than 15 mm into the batten.

(iii)

Purpose made clips of non-ferrous metal, stainless steel or steel protected from corrosion in accordance with Tables 3.5.1.2a and 3.5.1.2b.

(iv)

Flexible pointing material complying with AS 2050.

Table 3.5.2.1 Minimum fixing requirements

Design wind speed

Tile fixing - edge of roof

Tile fixing - field of roof

Ridge, hip, barge and valley tiles including capping (see Figure 3.5.2.2 )

N1 and N2

Fix every full tile in second course in from the edge of roof

In field of roof fix—

  1. every second tile in every course; or
  2. every tile in each alternative course. (see Figure 3.5.2.1b)

Fix each tile

N3

Fix each full tile in every second course starting from the second course in (see Figure 3.5.2.1c)

Fix every second full tile in every course (see Figure 3.5.2.1c)

Fix each tile

Note to Table 3.5.2.1: Refer to Figure 3.5.2.1 for determination of "edge of roof" and "field of roof".

Figure 3.5.2.1 Fixing of tile requirements
Diagram a Identification of field and edge of roof
v2_Fig3521a_2019.svg
Diagram b Minimum tile fixing requirements N1/N2
v2_Fig3521b_2019.svg
Diagram c Minimum tile fixing requirements N3
v2_Fig3521c_2019.svg

Explanatory information:

Explanatory information:

For the purpose of this Figure, "edge of roof" is a 1.2 m wide band bounded by the eaves, hips and barge measured towards the "ridge of roof".

Figure 3.5.2.2 Fixing of ridge and hip capping
Diagram a Fixing of ridge capping—ridge clip fixing
v2_Fig3522a_2019.svg
Diagram b Fixing of hip capping—clout or screw fixing
v2_Fig3522b_2019.svg

3.5.2.3 Flashing

Flashing for roof tiles must comply with the following:

(a)

Wall and step flashings:

(i)

For masonry or similar walls, flashing must—

(A)

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

(B)

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

(C)

have joints overlap the one below by not less than 75 mm in the direction of flow.

(ii)

For flashing where the upturn can be fixed to or behind the supporting frame or cladding, it must—

(A)

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

(B)

be fastened into or behind the wall cladding at each end and at a maximum of 600 mm centres; and

(C)

have joints overlap the one below by not less than 75 mm in the direction of flow.

(b)

Flashing of penetrations must—

(i)

be either collar, apron or other purpose made flashings; and

(ii)

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

(iii)

permit the total drainage of the area above the penetration.

(c)

Joints in flashing must be not less than 75 mm and lapped in the direction of fall of the roof.

(d)

Fixings for flashings must be compatible with the flashing material.

(e)

Lead flashings must not be used on any roof that is part of a potable drinking water catchment area.

(f)

Acceptable flashing configurations, including typical details for standard, and bedded and pointed valleys, are shown in Figure 3.5.2.3.

Figure 3.5.2.3 Acceptable flashing details
Diagram a Flashing abutting a masonry wall
v2_Fig3523a_2019.svg
Diagram b Flashing abutting a weatherboard wall or similar cladding
v2_Fig3523b_2019.svg
Diagram c Stepped flashing to a masonry wall
v2_Fig3523c_2019.svg
Diagram d Pipe penetration flashing
v2_Fig3523d_2019.svg
Diagram e Chimney flashing
v2_Fig3523e_2019.svg
Diagram f Standard valley
v2_Fig3523f_2019.svg
Diagram g Bedded and pointed valley for high rainfall areas (refer definition of low rainfall intensity area)
v2_Fig3523g_2019.svg

3.5.2.4 Sarking

Sarking must—

(a)

be provided in accordance with Table 3.5.2.2; and

(b)

comply with AS/NZS 4200.1 and be installed with—

(i)

each adjoining sheet or roll being—

(A)

overlapped not less than 150 mm; or

(B)

taped together; and

(ii)

sarking fixed to supporting members at not more than 300 mm centres; and

(iii)

no sags greater than 40 mm in the sarking.

Table 3.5.2.2 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

Notes to Table 3.5.2.2 :

  1. 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.
  2. All tiled roofs with a pitch less than 18 degrees must be provided with sarking, regardless of rafter/truss chord length.

Explanatory information:

Explanatory information:

Where sarking is also provided as reflective insulation for the purpose of energy efficiency, Part 3.12 contains required R-values and the necessary airspaces adjoining the reflective insulation.

3.5.2.5 Anti-ponding device/board

(a)

An anti-ponding device/board must be provided—

(i)

on sarked roofs with a pitch less than 20o; and

(ii)

on all roof pitches where there is no eaves overhang, regardless of whether sarking is required.

(b)

An anti-ponding device required by (a) 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 3.5.2.4).

3.5.2.6 Water discharge

Where an eaves gutter is provided in accordance with Part 3.5.3, tiles must overhang the fascia or tiling batten by not less than 35 mm (See Figure 3.5.2.4).

Figure 3.5.2.4 Typical installation of anti-ponding device/board
v2_Fig3524_2019.svg