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12.4

Part 12.4 Heating appliances, fireplaces, chimneys and flues

Part 12.4 Heating appliances, fireplaces, chimneys and flues

For the installation of a domestic solid fuel burning appliance, Part 12.4 need not be complied with if H7D5(a) is complied with.

An open fireplace, or solid-fuel burning appliance in which the fuel-burning compartment is not enclosed must have—

  1. all masonry constructed in accordance with H1D5; and
  2. a hearth constructed of stone, concrete, masonry or similar non-combustible material so that—
    1. it extends not less than 300 mm beyond the front of the fireplace opening and not less than 150 mm beyond each side of that opening; and
    2. its upper surface does not slope away from the back hearth (see Figure 12.4.2); and
    3. combustible material, such as flooring or framing members below or around the external edge of the hearth, is situated not less than 150 mm from the upper surface of the hearth (see Figure 12.4.2); and
  3. walls forming the sides and back of the fireplace up to a height of 300 mm above the underside of the arch or lintel which—
    1. are constructed in 2 separate leaves of solid masonry with a total combined thickness not less than 180 mm, excluding any cavity; and
    2. do not consist of concrete block masonry in the construction of the inner leaf; and
    3. are constructed of masonry units with a net volume, excluding cored and similar holes, not less than 75% of their gross volume, measured on the overall rectangular shape of the units, and with an actual thickness of not less than 100 mm; and
  4. the fireplace must be constructed on footings complying with 4.2.18.
Figure 12.4.2 Fireplace clearance from combustible materials
image-12-4-2-fireplace-clearance-from-combustible-materials.svg

The construction of a chimney must comply with H1D5 and the following:

  1. The walls of the chimney above the level referred to in 12.4.2(c) must be lined internally to a thickness of not less than 10 mm with composition mortar parging.
  2. The composition mortar in (a) must comply with AS 3700 or AS 4773 except that the mortar must be mixed by volume in the proportions of 1 part cement : 1 part lime : 5 parts sand.
  3. The chimney or flue must terminate not less than 300 mm above the highest part of the building within a horizontal distance of 3.6 m of the chimney or flue (see Figure 12.4.3).
Figure 12.4.3 Section showing height and position of chimney
image-12-4-3-section-showing-height-and-position-of-chimney.svg

Explanatory information

  • The requirements of this Part are to be read in conjunction with the building sealing requirements in Part 13.4. However, it should be noted that Part 13.4 does not apply in all States and Territories.
  • 12.4.3(a) requires the internal faces of masonry chimneys to be parged with a mortar to protect masonry elements and mortar beds from the corrosive by-products of combustion.

An insert fireplace and flue must comply with the following:

  1. The insert fireplace and flue must be—
    1. tested and passed the tests required by AS/NZS 2918; and
    2. fitted into a masonry fireplace (including chimney) constructed in accordance with H1D5 and Figure 12.4.4.
  2. The flue must be double skin and have been tested and pass the tests required by AS/NZS 2918.
  3. There must be a clearance of 50 mm between the outer flue and adjacent materials.
  4. The flue must terminate in accordance with Figure 12.4.3.
  5. The hearth must be constructed in accordance with 12.4.2(b) and (d).
Figure 12.4.4 Typical installation of fireplace flue inserts
image-12-4-4-typical-installation-of-fireplace-flue-inserts.svg

The installation of a free standing heating appliance must comply with the following:

  1. The appliance must—
    1. be installed with safety clearances determined by testing in accordance with AS/NZS 2918; or
    2. be located not less than 1.2 m from adjoining walls (other than a masonry wall); or
    3. have a heat shield between the adjoining wall (other than a masonry wall) and the heating appliance in accordance with Figure 12.4.5a and Figure 12.4.5b.
  2. Where a heat shield is used, it must be installed in accordance with Figure 12.4.5a and Figure 12.4.5b, and—
    1. have an FRL of not less than 60/60/60; or
    2. be not less than 90 mm thick masonry constructed in accordance with H1D5.
  3. The heating appliance must be installed on a hearth—
    1. complying with 12.4.2(b), except that the hearth must extend 400 mm from the front and sides of the appliance in accordance with Figure 12.4.5a and Figure 12.4.5b; or
    2. where a heat shield is installed, in accordance with Figure 12.4.5a and Figure 12.4.5b.
  4. The flue must—
    1. have been tested and passed the tests required by AS/NZS 2918; and
    2. be installed in accordance with Figure 12.4.5c; and
    3. terminate in accordance with Figure 12.4.3; and
    4. be flashed in accordance with H1D7.
  5. Flue types or installation of flues in areas not specifically covered by Figure 12.4.5a and Figure 12.4.5b and Figure 12.4.5c must be installed in accordance with AS/NZS 2918.
Figure 12.4.5a Acceptable location of free standing heating appliances — Elevation
image-12-4-5a-acceptable-location-of-free-standing-heating-appliances-elevation.svg
Figure 12.4.5b Acceptable location of free standing heating appliances — Plan view
image-12-4-5b-acceptable-location-of-free-standing-heating-appliances-plan-view.svg
Figure 12.4.5c Acceptable flue installation details
image-12-4-5c-acceptable-flue-installation-details.svg
Figure Notes
  1. Roof flashing – see H1D7(2).
  2. Hearth – see 12.4.5.
  3. Flue pipe size — 150 mm maximum (for other sizes see AS/NZS 2918).

Explanatory information

References to AS/NZS 2918 in 12.4.5(a)(i) and (d)(i) are only applicable in the context in which they are referred to in accordance with A4G1(2). 12.4.5(a) provides three options for the installation of free standing heating appliances. Where 12.4.5(a)(i) is chosen as a solution the free standing heating appliance must be installed with safety clearances determined by testing in accordance with AS/NZS 2918. 12.4.5(d)(i), in addition to (d)(ii) and (d)(iii), require the flue to be tested and have passed the tests required by AS/NZS 2918.