Timber Frame Metal Roof BAL-FZ Building Codes & Rules

- Comply with Bushfire Construction Requirements with Tools™: BAL-FZ requirements, fire danger insights, & detailed guidance for walls, roof, guttering & more!

AS 3959:2018, H3 (a)

≥ 300^{AS 3959:2018, H3 (a)}

AS 3959:2018, H3 (j) (iii)

Framing Angle^{AS 3959:2018, H3 (j) (iii)}

≥ 35 x 35 x 0.70mm BMT
≥ 600mm Fixing centres

AS 3959:2018, H3 (a)

≥ 10^{AS 3959:2018, H3 (a)}

FR Sealant

Timber

FR Plasterboard

Fibre-cement

FR Plasterboard

Joint Strip

BAL-FZ Certified

Eave Vents

Cover Angle

Plywood

Roof Framing

Plywood

Fully Sarked

Fire Resistant Sealant

AS 3959:2018, H3 (f)

Cover Angle^{AS 3959:2018, H3 (f)}

≥ 35 x 35 x 0.55mm BMT
≥ 600mm Fixing centres

Sarking

Glasswool Insulation

Industry Recommendation

AS 3959:2018, H3 (d)

Roof Fixings to Roof Edges^{Industry Recommendation}

Fascias, Bargeboards, Hips & Valleys
Every Corrugation
Optionally alternate fixings through Batten & Z Flashing^{AS 3959:2018, H3 (d)}

AS 3959:2018, H3 (d)

Fixing intervals at every 2nd Corrugation^{AS 3959:2018, H3 (d)}

AS 3959:2018, H3 (e)

Insulation^{AS 3959:2018, H3 (e)}

Compress Oversized Mineral Wool Strips between Sheet Ends & under Ridge Cap
≥ 115mm thk
≥ 110mm (W)

AS 3959:2018, 9.6.1 (c)

Roof Mounted Evaporative Coolers

NOT permitted in BAL-FZ^{AS 3959:2018, 9.6.1 (c)}

AS 3959:2018, H3 (c)

≥ R 1.8^{AS 3959:2018, H3 (c)}

AS 3959:2018, 9.6.3 (a)

Flammability Index ≤ 5^{AS 3959:2018, 9.6.3 (a)}

Tools™ Best Practice

Wider Gutter profile for easier cleaning^{Tools™ Best Practice}

AS 3959:2018, H3 (h)

FR Sealant^{AS 3959:2018, H3 (h)}

AS 3959:2018, H3 (j) (iii)

Framing Angle^{AS 3959:2018, H3 (j) (iii)}

≥ 35 x 35 x 0.70mm BMT
≥ 600mm Fixing centres

Tools™ Best Practice

Exhaust^{Tools™ Best Practice}

Cooking & Bathroom exhausts to Duct externally through Wall or Eaves to minimise condensation

AS 3959:2018, H3 (d)

Fixings to every

2nd Corrugation^{AS 3959:2018, H3 (d)}

Plywood

≥ 15mm T&G Plywood^[1]
Face Veneer perpendicular to Roof Structure

Plywood Membrane RULES

NCC 2022 V1

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

AS 3959:2018, H3 (a)

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{NCC 2022 Vol 1, G5NCC 2022 Vol 2, H7D4}
≥ 15mm T&G Plywood Membrane continuously fixed over Timber or Steel Roof Structure at^{AS 3959:2018, H3 (a)}
≥ 150mm CTS at the Panel End, &
≥ 300mm CTS at Trusses & Intermediate Rafter
≥ 10mm from Panel Edge
Face Veneer perpendicular to Roof Structure

AS 3959:2018, H3 (a)

≥ 15mm T&G Plywood^{AS 3959:2018, H3 (a)}
Face Veneer perpendicular to Roof Structure

Roofing Durability

AS 3959:2018, H3 (e)

Industry Recommendation

Insulation^{AS 3959:2018, H3 (e)}

Compressed Mineral Wool Strips
≥ 115mm thk
≥ 110mm (W)
Thickness may need to be reduced to be able to physically compress the Insulation under Roof Sheeting. Confirm acceptance with Certifying Authority prior to installation^{Industry Recommendation}

Wall & Floor BAL-FZ

AS 3959:2018, H3 (a)

≥ 150^{AS 3959:2018, H3 (a)}

Z Flashing

AS 3959:2018, H3 (e)

≥ 110^{AS 3959:2018, H3 (e)}

AS 3959:2018, H3 (g)

Z Flashing^{AS 3959:2018, H3 (g)}

40 x 40 x 40 x 0.55mm BMT
≥ 600mm Fixing centres along Eaves & into Plywood

Ridge Capping

Ventilation

Screen all vents & outlets^[1]
High level ventilation at Gable Ends preferred ^[2]

Ventilation RULES

NCC 2022 V3

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, 3.6.1

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

AS 3959:2018, 9.6.1

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{AS 3959:2018, 3.6.1NCC 2022 Vol 1, G5}
Fitted with non-combustible Ember Guards, or^{NCC 2022 Vol 2, H7D4}
Corrosion-resistant Steel or Bronze Perforated Sheet or Mesh with
≤ 2mm aperture size or opening^{AS 3959:2018, 9.6.1}

AS 3959:2018, 3.6.1

AS 3959:2018, 9.6.1 (b)

Screen all vents & outlets^{AS 3959:2018, 3.6.1}
High level ventilation at Gable Ends preferred ^{AS 3959:2018, 9.6.1 (b)}

Roof Sheet

0.42 to 0.6mm BMT^[1]
Junctions fully sealed^[2]
Non-combustible penetration sealed with Mineral Fibre^[3]

Sheet Roof MATERIALS

NCC 2022 V4

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, H3 (d)

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{AS 3959:2018, H3 (d)NCC 2022 Vol 1, G5}
0.42 to 0.6mm BMT^{NCC 2022 Vol 2, H7D4}
Hex Head Screw (Self-drilling) Fixing with EPDM seal & Shank Guard
On Battens, intervals at two corrugations
On Roof Edge, on all corrugations

Roofing RULES

NCC 2022 V4

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, 3.6.1

AS 3959:2018, 9.6.1 (a)

AS 3959:2018, 9.6.1 (b)

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{AS 3959:2018, 3.6.1AS 3959:2018, 9.6.1 (a)}
Screen all gaps^{AS 3959:2018, 9.6.1 (b)}, & the Roof to Wall & Roof to Roof junction be sealed by^{NCC 2022 Vol 1, G5}
Fascia & Eaves lining, or
Sealed on the junction between the top of the Wall & the Roof underside also between Rafters at the Wall line
Ventilation Openings^{NCC 2022 Vol 2, H7D4}
Fitted with non-combustible Ember Guards, or
Protected by corrosion-resistant Mesh or Perforated Sheet

Penetration RULES

NCC 2022 V3

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, 9.6.5

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{AS 3959:2018, 9.6.5NCC 2022 Vol 1, G5}
Seal openings with Fireproof Mineral Fiber, maintaining full function of penetrated elements^{NCC 2022 Vol 2, H7D4}
Use only non-combustible materials
Rooflights, Ventilators & Pipes or Conduit to be AS 1530.8.2 compliant

AS 3959:2018, H3 (d)

AS 2419.1:2005, H3 (d)

AS 3959:2018, 9.6.5 (a)

0.42 to 0.6mm BMT^{AS 3959:2018, H3 (d)}
Junctions fully sealed^{AS 2419.1:2005, H3 (d)}
Non-combustible penetration sealed with Mineral Fibre^{AS 3959:2018, 9.6.5 (a)}

Insulation

≥ 75mm Glasswool Blanket^[1]
Foil face down

Glasswool Insulation RULES

NCC 2022 V3

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, H3 (c)

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{AS 3959:2018, H3 (c)NCC 2022 Vol 1, G5}
Use Glasswool Blanket that strictly adhere to the following^{NCC 2022 Vol 2, H7D4}
≥ 75mm thk BAL-FZ Certified compressed Glasswool blanket with
Reflective Foil facing downwards fills the entire space between the Plywood Membrane & Sheet Roof
≥ 11kg/m³ Density
≥ R 1.8 R-value

AS 3959:2018, H3 (c)

≥ 75mm Glasswool Blanket^{AS 3959:2018, H3 (c)}
Foil face down

Gutter

Non-combustible materials^[1]

Gutter & Downpipes RULES

NCC 2022 V6

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, 9.6.7

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{AS 3959:2018, 9.6.7NCC 2022 Vol 1, G5}
Gutter & Downpipe installation^{NCC 2022 Vol 2, H7D4}
Downpipe requirement not covered
Non-combustible Gutter, Box Gutter & Valley Leaf Guards
Box Gutter flashed at Roof junction with non-combustible materials

AS 3959:2018, 9.6.7

Non-combustible materials^{AS 3959:2018, 9.6.7}

Battens

Timber or Steel Top Hat Battens with fixings as required by site location tie-down^[1]

Battens RULES

NCC 2022 V3

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, H3 (b)

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{AS 3959:2018, H3 (b)NCC 2022 Vol 1, G5}
Install Battens as mandated by the site location's tie-down requirements^{NCC 2022 Vol 2, H7D4}
Timber Batten
≤ 45 x 90mm securely fastened to Plywood, adhering to AS 1684, or
Steel Top Hat Battens
40mm (H) & 0.55mm thk securely fastened to Plywood to Roof Framing

AS 3959:2018, H3 (b)

Timber or Steel Top Hat Battens with fixings as required by site location tie-down^{AS 3959:2018, H3 (b)}

Fascias

Construction of Fascia^[1]
System to AS 1530.8.2
≥ 15mm Plywood
≥ 16mm Fire Rated Plasterboard
Timber Fascia

Fascias MATERIALS

NCC 2022 V4

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, H3 (i) (i)

AS 3959:2018, H3 (i) (ii)

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{AS 3959:2018, H3 (i) (i)AS 3959:2018, H3 (i) (ii)}
Construct the Fascia using materials that strictly adhere to the following^{NCC 2022 Vol 1, G5}
≥ 15mm Plywood Membrane installed on top of Timber, or Steel Truss Framing
≥ 16mm Water & Fire-resistant Plasterboard fixed into Plywood with
38mm x 6g Screws @ 150mm CTS per AS/NZS 2588
6 to 10mm Joint spacing to fill with Fire-resistant Sealant
Stagger Plywood joints when creating Butt Joints in the Plasterboard
Timber Fascia fixed on Roof structure per AS 1684^{NCC 2022 Vol 2, H7D4}

AS 3959:2018, H3 (i)

Construction of Fascia^{AS 3959:2018, H3 (i)}
System to AS 1530.8.2
≥ 15mm Plywood
≥ 16mm Fire Rated Plasterboard
Timber Fascia

Eaves

-/30/30 FRL or system to AS 1580.8.2^[1]
Construction Materials^[2]
≥ 15mm Plywood
≥ 16mm Fire Rated Plasterboard
≥ 4.5mm Fibre-cement Eave lining

Eaves RULES

NCC 2022 V2

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

AS 3959:2018, 9.6.6

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{NCC 2022 Vol 1, G5NCC 2022 Vol 2, H7D4}
Eaves Lining Installation^{AS 3959:2018, 9.6.6}
-/30/30 FRL or system to AS 1580.8.2
Penetrations protected with a non-combustible material
Ventilation openings fitted with Ember Guards
Seal the Joints using either Plastic Joining Strips or Timber Storm Moulds

Eaves RULES

NCC 2022 V4

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, 9.6.6 (c) (i)

AS 3959:2018, 9.6.6 (d)

AS 3959:2018, 9.6.6 (e)

AS 3959:2018, 9.6.6 (f)

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to NCC Specification 1, NCC Part G5, & AS 3959
-/30/30 FRL or system to AS 1580.8.2^{AS 3959:2018, 9.6.6 (c) (i)}
Penetrations protected with a non-combustible material^{AS 3959:2018, 9.6.6 (d)}
Ventilation openings fitted with Ember Guards^{AS 3959:2018, 9.6.6 (e)}
Seal the Joints using either Plastic Joining Strips or Timber Storm Moulds^{AS 3959:2018, 9.6.6 (f)}

Eaves MATERIALS

NCC 2022 V4

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, H3 (j) (i)

AS 3959:2018, H3 (j) (ii)

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to NCC Specification 1, NCC Part G5, & AS 3959
≥ 15mm Plywood installed on top of Timber, or Steel Truss Framing
≥ 16mm Water & Fire-resistant Plasterboard fixed into Plywood with^{AS 3959:2018, H3 (j) (i)}
38mm x 6g Screws @ 150mm CTS per AS/NZS 2588
≥ 4.5mm Fibre-cement Eaves to protect the Plasterboard^{AS 3959:2018, H3 (j) (ii)}

Penetration RULES

NCC 2022 V3

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, 9.6.5

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{AS 3959:2018, 9.6.5NCC 2022 Vol 1, G5}
Seal openings with Fireproof Mineral Fiber, maintaining full function of penetrated elements^{NCC 2022 Vol 2, H7D4}
Use only non-combustible materials
Rooflights, Ventilators & Pipes or Conduit to be AS 1530.8.2 compliant

Penetration RULES

NCC 2022 V4

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, 9.6.5 (a)

AS 3959:2018, 9.6.5 (b)

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to NCC Specification 1, NCC Part G5, & AS 3959
Seal openings with Fireproof Mineral Fiber, maintaining full function of penetrated elements^{AS 3959:2018, 9.6.5 (a)}
Use only non-combustible materials^{AS 3959:2018, 9.6.5 (a)}
Rooflights, Ventilators & Pipes or Conduit to be AS 1530.8.2 compliant^{AS 3959:2018, 9.6.5 (b)}

Eaves MATERIALS

NCC 2022 V3

All Building Classes

NCC 2022 G5, H7D4, & S1

[2019 G5, 3.10.5, Sch 5]

May 2023

AS 3959:2018, H3 (j)

NCC 2022 Vol 1, G5

NCC 2022 Vol 2, H7D4

Building elements within Bushfire-prone Areas to be Bushfire Attack Resistant to the NCC^{AS 3959:2018, H3 (j)NCC 2022 Vol 1, G5}
Eaves construction materials^{NCC 2022 Vol 2, H7D4}
≥ 15mm Plywood installed on top of Timber, or Steel Truss Framing
≥ 16mm Water & Fire-resistant Plasterboard fixed into Plywood with
38mm x 6g Screws @ 150mm CTS per AS/NZS 2588
≥ 4.5mm Fibre-cement Eaves to protect the Plasterboard

AS 3959:2018, 9.6.6 (c) (i)

AS 3959:2018, H3 (j)

-/30/30 FRL or system to AS 1580.8.2^{AS 3959:2018, 9.6.6 (c) (i)}
Construction Materials^{AS 3959:2018, H3 (j)}
≥ 15mm Plywood
≥ 16mm Fire Rated Plasterboard
≥ 4.5mm Fibre-cement Eave lining

Roof Construction BAL-FZ (Light Steel)