NCC 2016 Volume Two
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Part 3.7.1 Fire Separation
Appropriate Performance Requirements
Appropriate
Where an alternative fire separation design is proposed as a Performance Solution to that described in Part 3.7.1, that proposal must comply with—
- P2.3.1 ; and
- the relevant Performance Requirements determined in accordance with 1.0.7.
3.7.1.1 Application
Compliance with this acceptable construction practice satisfies Performance RequirementP2.3.1 for fire separation.
3.7.1.2 General concession — non-combustible materials
The following materials, though combustible or containing combustible fibres, may be used wherever a non-combustible material is required in the Housing Provisions—
(a)
plasterboard; and
(b)
perforated gypsum lath with a normal paper finish; and
(c)
fibrous-plaster sheet; and
(d)
fibre-reinforced cement sheeting; and
(e)
pre-finished metal sheeting having a combustible surface finish not exceeding 1 mm thick and where the Spread-of-Flame Index of the product is not more than 0; and
(f)
bonded laminated materials where—
(i)
each laminate is non-combustible; and
(ii)
each adhesive layer is not more than 1 mm thick; and
(iii)
the total thickness of adhesive layers is not more than 2 mm; and
(iv)
the Spread-of-Flame Index and the Smoke-Developed Index of the laminated material as a whole does not exceed 0 and 3 respectively.
3.7.1.3 External walls of Class 1 buildings
An external wall of a Class 1 building, and any openings in that wall, must comply with 3.7.1.5 if the wall is less than—
(a)
900 mm from an allotment boundary other than the boundary adjoining a road alignment or other public space; or
(b)
1.8 m from another building on the same allotment other than an appurtenant Class 10 building or a detached part of the same Class 1 building.
STATE AND TERRITORY VARIATIONS
State and Territory Variations
In South Australia delete 3.7.1.3(b) and insert SA 3.7.1.3(b) and (c) as follows:
(b)
1.8 m from another building on the same allotment other than an appurtenant Class 10 building or a detached part of the same Class 1 building; or
(c)
3 m from a brush fence.
3.7.1.4 Measurement of distances
(a)
The distance from any point on an external wall of a building to an allotment boundary or another building is the distance to that point measured along a line at right angles from the allotment boundary or external wall of the other building which intersects that point without being obstructed by a wall complying with 3.7.1.5.
(b)
Where a wall within a specified distance is required to be constructed in a certain manner, only that part of the wall (including any openings) within the specified distance need be constructed in that manner.
(see Figure 3.7.1.1 and 3.7.1.2a)
(c)
Where the distance measured is between buildings of different heights, the distance must be taken from the external wall with the highest elevation measured at right angles to a point that intersects a vertical projection above the adjacent wall (see Figure 3.7.1.2b).
STATE AND TERRITORY VARIATIONS
STATE AND TERRITORY VARIATIONS
In South Australia after 3.7.1.4(c) insert SA 3.7.1.4(d) as follows:
(d)
The distance from any point on an of a building to a brush fence is measured in any direction from the external wall.
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Figure 3.7.1.1 WALLS AT RIGHT ANGLES TO THE BOUNDARY |
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| Notes: |
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Figure 3.7.1.2a MEASUREMENT OF DISTANCES (Plan view) |
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| Diagram a. | Full wall protection |
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| Diagram b. | Part walls protection |
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| Note: Setback distance is measured at right angles to the boundary. | |
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Figure 3.7.1.2b MEASUREMENT OF DISTANCE — BUILDINGS OF DIFFERENT HEIGHTS |
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| Class 1 buildings on same allotment |
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3.7.1.5 Construction of external walls
(a)
(including gables) required to be fire-resisting (referred to in 3.7.1.3 or 3.7.1.6) must extend to the underside of a non-combustible roof covering or non-combustible eaves lining (See Figure 3.7.1.3) and must—
(i)
have an FRL of not less than 60/60/60 when tested from the outside; or
(ii)
be of masonry-veneer construction in which the external masonry veneer is not less than 90 mm thick; or
(iii)
be of masonry construction not less than 90 mm thick.
Explanatory information
Explanatory information:
The intent of the typical construction details shown in Figure 3.7.1.3 is to ensure that combustible materials (external or internal) are not directly exposed to fire at the junction of the wall and non-combustible roof, eaves lining, guttering and the like. Other forms of construction may also be acceptable provided that they achieve this intent.
See Figure 3.7.1.10 and 3.8.6.3 for internal separating wall construction under one common roof.
(b)
Openings in external walls required to be fire-resisting (referred to in 3.7.1.3 or 3.7.1.6) must be protected by—
(i)
non-openable fire windows or other construction with an FRL of not less than –/60/–; or
(ii)
self-closing solid core doors not less than 35 mm thick.
(c)
Subfloor vents, roof vents, weepholes, control joints, construction joints and penetrations for pipes, conduits and the like need not comply with (b).
(d)
Concessions for non-habitable room windows.
Despite the requirements in (b), in a non-habitable room, a window that faces the boundary of an adjoining allotment may be not less than 600 mm from that boundary or, where the window faces another building on the same allotment, not less than 1200 mm from that building provided that—
(i)
in a bathroom, laundry or toilet, the opening has an area of not more than 1.2 m2; or
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Figure 3.7.1.3 TYPICAL CONSTRUCTION OF EXTERNAL WALLS |
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Notes:
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3.7.1.6 Class 10a buildings
(a)
Where a Class 10a building is located between a Class 1 building and the allotment boundary, other than the boundary adjoining a road alignment or other public space, the Class 1 building must be protected by one of the following methods shown in Figure 3.7.1.4.
(b)
Where a Class 10a building is located between a Class 1 building to which it is appurtenant and another building on the same allotment, the Class 1 building must be protected by one of the methods shown in Figure 3.7.1.5.
(c)
Where two or more Class 10a buildings on the same allotment are appurtenant to different Class 1 buildings, the Class 10a buildings must be separated in accordance with one of the methods shown in Figure 3.7.1.6.
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Figure 3.7.1.4 PROTECTION OF CLASS 1 BUILDINGS — CLASS 10a BETWEEN CLASS 1 AND THE ALLOTMENT BOUNDARY |
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Legend: |
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Wall with an FRL of 60/60/60 |
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Allotment boundary |
| a. 900 mm from allotment boundary | |||
| The Class 10a building is not less than 900 mm from the allotment boundary, other than the boundary adjoining a road alignment or other public space. |
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| b. External wall to Class 10a building with FRL | |||
| An external wall of the Class 10a building which is less than 900 mm from an allotment boundary, other than the boundary adjoining a road alignment or other public space, complies with 3.7.1.5. |
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| c. External wall to Class 10a building with FRL | |||
| An external wall of the Class 10a building which is less than 900 mm from the Class 1 building complies with 3.7.1.5. |
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| d. 900 mm separation between buildings | |||
| The Class 1 building is not less than 900 mm from the Class 10a building. |
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| e. Class 1 building with FRL to external wall | |||
| An external wall of the Class 1 building which is less than 900 mm from the Class 10a building complies with 3.7.1.5. |
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Figure 3.7.1.5 PROTECTION OF CLASS 1 BUILDINGS — CLASS 10a BETWEEN CLASS 1 AND OTHER BUILDINGS ON ALLOTMENT |
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Legend: |
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Wall with an FRL of 60/60/60 |
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Other Class of building on allotment |
| a. 1.8 m from other building on allotment | |||
| The Class 10a building is not less than 1.8 m from the other building. |
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| b. External wall to Class 10a building with FRL | |||
| An external wall of the Class 10a building which is less than 1.8 m from the other building complies with 3.7.1.5. |
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| c. External wall to Class 10a building with FRL | |||
| An external wall of the Class 10a building which is less than 1.8 m from the Class 1 building complies with 3.7.1.5. |
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| d. 1.8 m separation between Class 1 and 10a | |||
| The Class 1 building is not less than 1.8 m from the Class 10a building. |
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| e. Class 1 building with FRL to external wall | |||
| An external wall of the Class 1 building which is less than 1.8 m from the Class 10a building complies with 3.7.1.5. |
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Figure 3.7.1.6 PROTECTION OF CLASS 1 BUILDINGS — SEPARATION OF CLASS 10a BUILDINGS ON AN ALLOTMENT |
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| Legend: |
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Wall with a FRL of 60/60/60 |
| a. 1.8 m between Class 10a buildings | ||
| Each 10a must be separated from each other by a distance of not less than 1.8 m. |
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| b.External wall to Class 10a building with FRL | ||
| Each 10a must be separated from each other by external walls complying with 3.7.1.5. |
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| c. 900 mm separation between Class 10a and Class 1 buildings | ||
| Each 10a must be separated from each Class 1 building by a distance of not less than 900 mm. |
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| d.External wall to Class 10a buildings with FRL | ||
| Each 10a must be separated from each Class 1 building by external walls complying with 3.7.1.5. |
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| e. Class 10a buildings with FRL to separating wall | ||
| Each 10a must be separated by a wall complying with 3.7.1.8. |
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(d)
A carport is exempt from (a), (b) and (c) if—
(i)
it has two or more sides open and not less than one third of its perimeter open and, for the purposes of this clause, a side is considered to be open if the roof covering adjacent to that side is not less than 500 mm from another building or allotment boundary; and
(ii)
it has a polycarbonate or non-combustible roof covering and any ceiling lining and wall cladding, including gables, is also non-combustible (see Figure 3.7.1.7); and
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Figure 3.7.1.7 IDENTIFYING AN OPEN CARPORT |
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(iii)
it does not provide direct vertical support to any part of the Class 1 building; and
(iv)
in the case where it has a common roof structure with the Class 1 building and the carport does not have a ceiling (see Figure 3.7.1.8), the opening between the top of the wall of the Class 1 building and the underside of the roof covering is infilled with—
(A)
a non-combustible material; or
(B)
construction clad with non-combustible material on the carport side.
STATE AND TERRITORY VARIATIONS
STATE AND TERRITORY VARIATIONS
In South Australia delete 3.7.1.6(d) and insert SA 3.7.1.6(d) as follows:
(d)
A carport or verandah is exempt from (a), (b) and (c) if—
(i)
it has—
(A)
two or more sides open and not less than one third of its perimeter open and, for the purpose of this clause, a side is considered to be open if the roof covering adjacent to that side is not less that 500 mm from another building or allotment boundary; or
(B)
any part of the external wall of the Class 1 building located less than 2 m from the allotment boundary or less than 4 m from another Class 1 building on the same allotment is fire-resisting to the underside of a non-combustible roof covering or to the underside of a non-combustible ceiling lining (see Figures SA 3.7.1.7a, SA 3.7.1.7b and SA 3.7.1.7c); and
(ii)
it has polycarbonate or non-combustible roof covering and any ceiling lining and wall cladding, including gables, is also non-combustible (see Figure 3.7.1.7); and
(iii)
it does not provide direct vertical support to any part of the Class 1 building; and
(iv)
in the case where it has a common roof structure with the Class 1 building and the carport or verandah does not have a ceiling (see Figure 3.7.1.8), the opening between the top of the wall of the Class 1 building and the underside of the roof covering is infilled with—
construction clad with non-combustible material on the carport or verandah side; and
(v)
in the case where two carports or verandahs have a common roof structure with two different Class 1 buildings and the carports or verandahs have a ceiling, the roof space or ceiling space between the top of the ceiling and the underside of the roof covering is infilled as follows—
(A)
vertically between the two Class 1 buildings and between the two appurtenant carports of verandahs in accordance with SA 3.7.1.6(d)(iv) (see Figure SA 3.7.1.7d); or
(B)
vertically between the two Class 1 buildings and between the two appurtenant carports or verandahs in accordance with SA 3.7.1.6(d)(iv), except that the construction must be clad with non-combustible materials on both sides and must not be crossed by timber or other combustible building elements except for roof battens with dimensions of 75 × 50 mm or less, roof sarking-type material or a timber gutter board not less than 20 mm thick.
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Figure SA 3.7.1.7a Fire-resisting requirements for carports or verandahs without a ceiling |
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:
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Figure SA 3.7.1.7b Fire-resisting requirements for carports or verandahs with a non-combustible ceiling |
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Figure SA 3.7.1.7c Fire-resisting requirements for external walls in carports and verandahs that share a common roof space |
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Figure SA 3.7.1.7d Fire-resisting requirements for roof space openings in carports and verandahs with a ceiling that share a common roof space |
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Figure 3.7.1.8 REQUIREMENTS FOR NON-COMBUSTIBLE INFILL PANELS TO CARPORT |
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(e)
Class 10a buildings must not significantly increase the risk of spread of fire between Class 2 to 9 buildings.
STATE AND TERRITORY VARIATIONS
STATE AND TERRITORY VARIATIONS
In South Australia after 3.7.1.6(e) insert SA 3.7.1.6(f) and (g) as follows:
(f)
A carport or verandah may have timber posts and timber roof support beams regardless of the distance from the boundary.
(g)
A Class 10b brush fence must not be constructed within 3 m of a Class 1 building unless any part of the building within 3 m of the brush fence complies with the fire-resisting requirements of 3.7.1.3, 3.7.1.4, 3.7.1.5 and 3.7.1.7.
3.7.1.7 Allowable encroachments
(a)
An encroachment is any construction between the external wall of the building and the allotment boundary other than a boundary adjoining a road or other public space, or the external walls of two buildings on the same allotment and relates to any external wall of—
(ii)
a Class 1 building.
(b)
The encroachments allowed within 900 mm of an allotment boundary or within 1.8 m of another building on the same allotment are—
(i)
fascias, gutters and downpipes; and
(ii)
eaves with non-combustible roof cladding and non-combustible lining; and
(iii)
flues, chimneys, pipes, domestic fuel tanks, cooling or heating appliances or other services; and
(iv)
light fittings, electricity or gas meters, aerials or antennas; and
(v)
pergolas, sun blinds or water tanks; and
(vi)
unroofed terraces, landings, steps and ramps, not more than 1 m in height.
(c)
Encroachments listed in (b)(i), if combustible, (b)(ii) and (b)(iii) must not be built within 450 mm of an allotment boundary nor be built within 900 mm of the external wall or associated encroachments of another building on the same allotment (see Figure 3.7.1.9).
Explanatory information
Explanatory information:
A deck is not considered an unroofed terrace and is therefore not permitted as an allowable encroachment under 3.7.1.7(b) whether combustible or not.
The term pergola is a reference to an unroofed structure.
STATE AND TERRITORY VARIATIONS
STATE AND TERRITORY VARIATIONS
In South Australia delete 3.7.1.7 and insert SA 3.7.1.7 and Figure SA 3.7.1.9a as follows:
(a)
An encroachment is any construction between the external wall of the building and the allotment boundary other than a boundary adjoining a road or other public space, between the external wall of the building and a brush fence, or between the external walls of two buildings on the same allotment and relates to any external wall
(b)
The encroachments allowed within 900 mm of an allotment boundary, within 1.8 m of another building on the same allotment or within 3 m of a brush fence are—
(i)
fascias, gutters, downpipes; and
(ii)
eaves with non-combustible roof cladding and non-combustible lining; and
(iii)
flues, chimneys, pipes, domestic fuel tanks, cooling or heating appliances or other services; and
(iv)
light fittings, electricity or gas meters, aerials or antennas; and
(v)
pergolas, sun blinds or water tanks; and
(vi)
unroofed terraces, landings, steps and ramps, not more than 1 m in height.
(c)
Except as permitted by (d) encroachments listed in (b)(i), if combustible, (b)(ii) and (b)(iii) must not be built within 450 mm of an allotment boundary nor be built within 900 mm of the external wall or associated encroachments of another building on the same allotment (see Figure 3.7.1.9).
(d)
Eaves with non-combustible roof cladding and non-combustible soffit or lining may encroach within 450 mm of the allotment boundary where the external walls of a building are located not less than 900 mm from the allotment boundary and the walls are positioned at an angle of not less than 20 degrees and not more than 70 degrees to the allotment boundary or other building and the eaves only encroach at the corner of the roof (see SA Figure 3.7.1.9a).
(e)
Fascias listed in (b)(i), if combustible, must not be built within 3 m of a brush fence.
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Figure SA 3.7.1.9a Concession for encroachment of eaves |
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Figure 3.7.1.9 ALLOWABLE ENCROACHMENTS FOR NON-COMBUSTIBLE CONSTRUCTION |
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3.7.1.8 Separating walls
(a)
A separating wall between Class 1 buildings, or a wall that separates a Class 1 building from a Class 10a building which is not appurtenant to that Class 1 building must have an FRL of not less than 60/60/60 and—
(i)
commence at the footings or ground slab (see Figure 3.7.1.10); and
(ii)
extend—
(A)
if the building has a non-combustible roof covering, to the underside of the roof covering (see Figure 3.7.1.10 and Figure 3.7.1.11); or
(B)
if the building has a combustible roof covering, to not less than 450 mm above the roof covering (see Figure 3.7.1.10).
(b)
Where parts of a Class 1a dwelling are located above a Class 10a private garage which is not appurtenant to that Class 1a dwelling, any wall separating parts of the Class 1a dwelling from a non-appurtenant private garage must—
(i)
have an FRL of not less than 60/60/60 when tested from the non-appurtenant private garage side; and
(ii)
extend to the underside of a separating floor complying with 3.7.1.11.
(c)
A separating wall of lightweight construction must be tested in accordance with Specification C1.8 of the BCA Volume One.
STATE AND TERRITORY VARIATIONS
STATE AND TERRITORY VARIATIONS
In New South Wales delete 3.7.1.8(b) and insert NSW 3.7.1.8(b) as follows:
(b)
* * * * *
Note: The New South Wales Additions contain requirements for a Class 1a dwelling located above a non-appurtenant Class 10a private garage.
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Figure 3.7.1.10 SEPARATING WALL CONSTRUCTION |
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(d)
A separating wall complying with (a)(ii)(A)—
(i)
must not be crossed by timber or other combustible building elements except for roof battens with dimensions of 75x50 mm or less, or roof sarking; and
(ii)
must have any gap between the top of the wall and the underside of the roof covering packed with mineral fibre or other suitable fire-resisting material.
(e)
Where a building has a masonry veneer external wall, any gap between the separating wall and the external masonry veneer must be—
(i)
not more than 50 mm; and
(ii)
packed with a mineral fibre or other suitable fire resistant material with the packing arranged to maintain any weatherproofing requirements of Part 3.3.4.
(f)
Eaves, verandahs and similar spaces that are open to the roof space and are common to more than one Class 1 dwelling must be separated by a non-combustible vertical lining (see Figure 3.7.1.11 Diagram b).
(g)
Any service opening, other than those listed in (h), (i) and (j), in a separating wall must have construction with an FRL of not less than -/60/60.
(h)
If an electrical wire or cable penetrates a separating wall—
(i)
the service and building element at the penetration must be identical with a prototype assembly which has been tested in accordance with AS 4072.1 and AS 1530.4 and achieved an FRL of not less than -/60/60; or
(ii)
the service must be installed so that—
(A)
the opening is neatly formed, cut or drilled and no closer than 50 mm to any other service; and
(B)
the opening is no larger in cross-section than—
(aa)
2000 mm2 if only a single cable is accommodated and the gap between the cable and the wall is no wider than 15 mm; or
(bb)
500 mm2 in any other case; and
(C)
any gap between the service and the wall is packed with mineral fibre or other suitable fire resistant material.
(i)
If an electrical switch, outlet, socket or the like is accommodated in a separating wall—
(i)
the service and building element at the penetration must be identical with a prototype assembly which has been tested in accordance with AS 4072.1 and AS 1530.4 and achieved an FRL of not less than -/60/60; or
(ii)
the service must be installed so that—
(A)
the opening or recess must not—
(aa)
be located opposite any point within 300 mm horizontally or 600 mm vertically of any opening or recess on the opposite side of the wall; or
(bb)
extend beyond half the thickness of the wall; and
(B)
any gap between the service and the wall is packed with mineral fibre or other suitable fire resistant material.
(j)
Other than where a tested system is used in accordance with (i)(i), if an electrical switch, socket, outlet or the like is accommodated in a hollow separating wall (such as a stud wall, masonry cavity wall or a wall of hollow blockwork), the cavity immediately behind the service must be framed and packed with mineral fibre or other suitable fire resistant material (see Figure 3.7.1.11 Diagram c).
Explanatory information
Explanatory information:
It is important that any opening in a separating wall between Class 1 buildings not allow the free passage of fire between the buildings. On the other hand, many designs would require the installation of openings for electrical cables and outlets in these walls. 3.7.1.8(g) therefore allows such openings provided they have an FRL of at least -/60/60 or comply with the details set out in 3.7.1.8(h), (i) and (j).
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Figure 3.7.1.11 SEPARATING WALL CONSTRUCTION—UNDERSIDE OF NON-COMBUSTIBLE ROOF CLADDING |
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| Diagram a. | |
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| Diagram b. | |
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Diagram c. |
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3.7.1.9 Fire hazard properties
The fire hazard properties of materials used in a Class 1 building, including common floor or ceiling spaces with a Class 10 building, must comply with the following:
(a)
Sarking-type materials used in the roof must have a flammability index not greater than 5.
(b)
Flexible ductwork used for the transfer of products initiating from a heat source that contains a flame must comply with the fire hazard properties set out in AS 4254 Parts 1 and 2.
3.7.1.10 Roof lights
Combustible roof lights, skylights or the like installed in a roof or part of a roof required to have a non-combustible covering must—
(a)
have an aggregate area not more than 20% of the roof or part of the roof; and
(b)
be not less than—
(i)
900 mm from—
(A)
the allotment boundary other than the boundary adjoining a road alignment or other public space; and
(B)
the vertical projection of a separating wall extending to the underside of the roof covering; and
(ii)
1.8 m from any roof light or the like in another building on the allotment other than an appurtenant building or a detached part of the same building. (See Figure 3.7.1.12).
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Figure 3.7.1.12 LOCATION OF COMBUSTIBLE ROOF LIGHTS |
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| Note: Roof lights depicted in Figure 3.7.1.12 are combustible. |
3.7.1.11 Separating floors
(a)
Where parts of a Class 1a dwelling are located above or below a Class 10a private garage which is not appurtenant to that Class 1a dwelling, any floor separating the Class 1a dwelling from the non-appurtenant Class 10a private garage must—
(i)
be a floor/ceiling system incorporating a ceiling which has a resistance to the incipient spread of fire to the space above itself of not less than 60 minutes; or
(ii)
have an FRL not less than 30/30/30 when tested from the underside; or
(iii)
have a fire-protective covering on the underside of the floor, including beams incorporated in it, if the floor is combustible or of metal.
(b)
Where a floor subject to (a)(ii) depends on direct vertical or lateral support from another part to maintain its FRL, that supporting part must have an FRL of not less than 30/-/-.
(c)
Where a service passes through a floor referred to in (a), the penetration must not reduce the fire performance of the floor or covering.
(See Figure 3.7.1.13)
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Figure 3.7.1.13 SEPARATING WALL AND FLOOR CONSTRUCTION |
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STATE AND TERRITORY VARIATIONS
STATE AND TERRITORY VARIATIONS
3.7.1.11 does not apply in New South Wales.
Note: The New South Wales Additions contain requirements for a Class 1a dwelling located above a non-appurtenant Class 10a private garage.