Part 13.2 Building fabric
NSW 13.2.1 Application of Part 13.22019: NSW 3.12.1
NSW 13.2.3 Roofs and ceilings2019: NSW 126.96.36.199
- has metal sheet roofing directly fixed to metal purlins, metal rafters or metal battens; and
- does not have a ceiling lining or has a ceiling lining fixed directly to those metal purlins, metal rafters or metal battens,
must have a thermal break, consisting of a material with an R-Value of greater than or equal to 0.2, installed between the metal sheet roofing and its supporting metal purlins, metal rafters or metal battens.
NSW 13.2.4 Roof lights
NSW 13.2.5 External walls2019: NSW 188.8.131.52
- does not have a wall lining or has a wall lining that is fixed directly to the metal frame; and
- is clad with weatherboards, fibre-cement or the like, or metal sheeting fixed to the metal frame.
- A lightweight wall has no high thermal mass cladding on the outside or lining on the inside. Typically, this would represent a framed wall, clad externally with timber weatherboards, fibre-cement sheet, metal or autoclaved aerated concrete.
- Because of the high thermal conductance of metal, a thermal break is needed when a metal framing member directly connects the external cladding to the internal lining or the internal environment. For the purposes of NSW 13.2.5(1)(b), expanded polystyrene strips greater than or equal to 12 mm thickness and timber greater than or equal to 20 mm thickness are deemed to achieve an R-Value greater than or equal to 0.2.
- Continuous insulation placed outside the primary insulation layer, including reflective insulation, may also be subject to vapour permeance requirements of 10.8.1(2). Many continuous insulation products and foils have a low vapour permeance. Some reflective insulation products have perforations to increase their vapour permeance. Many perforated reflective insulation products are not classified as a water barrier by AS 4200.1. Accordingly, these products are not suitable for use as a water control layer.
- Many reflective insulation products that use perforations to increase their vapour permeance are not suitable for use behind vertical or diagonally orientated timber cladding boards, where required by clause 7.5.2 of the ABCB Housing Provisions, or behind open jointed or unsealed cladding systems.
NSW 13.2.6 Floors and subfloor walls2019: NSW 184.108.40.206
- be water resistant; and
- be continuous from the adjacent finished ground level—
- to a depth of greater than or equal to 300 mm; or
- for at least the full depth of the vertical edge of the concrete slab-on-ground (see Figure 13.2.6).
- NSW 13.2.6(3) provides an exemption for an in-screed heating or cooling system used solely in bathrooms, amenity areas and the like, as these are typically small areas.
- Care should be taken to ensure that the type of termite management system selected is compatible with the slab edge insulation.