Protecting life and property against bushfires is an increasingly important aspect of any new construction project.
The disastrous bushfires of 2009 forced a major rethink of the old bushfire standards. The resulting legislation identified 6 levels of bushfire protection and is known as BAL (Bushfire Attack Level).
Each level recognises an increasing degree of risk from bushfires depending on a range of factors including the proximity to large areas of bush.
What's a BAL 40 Rating?
The BAL 40 (very high) is the second highest bushfire attack level and is designed to protect buildings from catching fire in the presence of windborne embers and smaller secondary fires triggered by those embers.
BUSHFIRE ATTACK LEVEL (BAL)
DESCRIPTION OF PREDICTED BUSHFIRE ATTACK AND LEVELS OF EXPOSURE
BAL - Low
There is not sufficient risk to warrant exposure
BAL - 12.5
BAL - 19
Increasing levels of ember attack and burning debris ignited by wind borne embers together with increasing heat flux between 12.5 and 19kW/m2
BAL - 29
Increasing levels of ember attack and burning debris ignited by wind borne embers together with increasing heat flux between 19 and 29kW/m220
Increasing levels of ember attack and burning debris ignited by wind borne embers together with increasing heat flux with the increased likelihood of exposure to flames
Direct exposure to flames from fire front in addition to heat flux and ember attack
BAL 40 is also designed to protect buildings from some direct exposure to flames and high radiant heat (up to 40kW/m2).
The BAL 40 regulations stipulate the design and types of materials you can use in most external aspects of your new build including:
- External walls
- Floors & subfloors
- External windows & doors
- Verandas, decks & patios
- Water & gas supply pipes
The BAL 40 requirements can add significantly to the cost of building so make sure you do your homework.Floors & subfloorsVerandas, decks & patios
Thinking carefully about your design and material choices before you start can make a big difference to the final cost of your project.
BAL 40 Cladding
External walls must be made from non-combustible materials such as cavity brick, concrete, mud brick, stone, fibre cement panels (min 9mm thick) or steel cladding.
Here at No1. Roofing & Building we have a number of attractive fibre cement cladding options ranging from smooth, flat facade boards through to various weatherboard profiles.
We supply all the best known Australian fibre cement brands including:
- James Hardie
We also offer the enormous range of Colorbond steel cladding options.
Kingspan Steel also offer some really special steel architectural panel options that will allow you to fulfil your wildest creative visions.
Checkout the extraordinary abilities of KingZip if you’re looking at creating a complex building envelope.
Insulated panels are making real waves in the Australian construction scene today.
Kingspan and Bondor are two companies leading the way with superior insulated panels that meet BAL 40 requirements as well as deliver stunning looks, exceptional thermal performance, and cost savings.
BAL 40 Roofing
Obviously, windblown embers tend to settle on a roof making it one of the most critical ignition points for any building.
Colorbond Steel is one of the most popular roof cladding products in Australia. It comes in an exciting range of colours and it meets all requirements for building bushfire zones including up to BAL 40 and BAL FZ.
Colorbond Steel is manufactured using Australian-made Bluescope steel and provides a solid line of defence against ember attack as well as flame resistance for your new build.
Colorbond Steel also offers some exciting architectural panel profiles including:
This exciting range of architectural roofing panel systems delivers real performance and protects your home with real style.
BAL 40 Building Materials
BAL 40 requirements also cover a range of miscellaneous building materials.
Insulation not only helps to keep your building warm in winter and cool in summer but it also performs an important role in retarding the progress of flames into roof and wall cavities.
We supply a range of BAL 40 rated insulation products including:
- Bradford Multitel, Fireseal, & Anticon blankets
- HardieFire mineral wool insulation
- Fletcher Fire Stop Batts
We provide insulation for all types of cladding including metal and tile.
Bradford Fireseal Insulation
The Bradford Fireseal range is made from non-combustible Rockwool, an insulation material specially formulated to provide fire protection.
It is manufactured by spinning a molten mixture of natural rock and recycled blast furnace waste products into fibres which are bonded with a thermosetting resin.
The Bradford Fireseal range includes products that meet fire regulations for specific applications, such as:
- Party walls
- Curtain walls
- BAL – 12.5 to BAL – 40 and BAL – FZ rated
- Damper strips
Bradford Multitel™ BAL Blanket
Bradford Multitel™ BAL 12.5-40 is used to seal off areas from potential ember ingress in bushfire prone areas.
Bradford Multitel is manufactured from an engineered glasswool insulation blanket.
The blanket is manufactured by spinning molten glass, containing up to 80% recycled content, into fine wool like fibres.
These are bonded together using a thermosetting resin. The product can be identified by its golden appearance.
Bradford Anticon Roofing Blanket
All modern homes should be as fire resistant as possible.
Upgrading your roof with Bradford Anticon means you can enjoy peace of mind knowing that your roof insulation is made from non-combustible fibres, suited to meet the requirements for metal roofs in bushfire rated areas.
Due to the flammability of some silicones it’s vital that you choose the correct silicone sealants and adhesives for BAL 40 ratings.
Fire rated sealants can also prevent the passage of embers into roof or wall cavities. Our wide range of fire rated sealants and adhesives includes:
- Bostik Fireban One sealant
- Soudal Soudaseal FR
Soudal Soudaseal FR
Soudaseal FR is a high-quality, fire-resistant, smoke-tight, neutral, elastic, one component joint and adhesive sealant based on SMX Polymer (Hybrid).
- Fire retardant expansion and connection joints in the construction industry.
- Sealing of fire-retardant joints in prefab buildings and skyscrapers.
- Flexible connections in automotive applications.
- As part of the ‘Soudal Fire Range’ assortment for penetration seals and joints.
Gardiner Australia manufactures a huge range of foam infill strips to match all standard and many non-standard cladding profiles.
Infill strips play an important role in protecting the gaps under ridge capping and steel sheet ends from dust, moisture and the entry of embers. Gardiner infill strips are rated up to BAL FZ.
Gardiner infill strips are Australian manufactured foam material for "PE" standard roof infill strips and conform to the bushfire standards AS 1530.1 (BAL FZ)
They provide an effective barrier to air, water & dust, and are manufactured from closed cell foam they will also not absorb ambient moisture that can cause rust on metal roofs, and are available in a variety of colours.
Weep Hole Screens
If you’re building with brick or masonry then you’ll want to protect weep holes with Weepa. Weepa provide a range of attractive weep hole protectors that are rated up to BAL FZ.
Choosing the correct Weepa
High Performance Bushfire Weepa
Bushfire compliance AS3959:2018 BAL-LOW, BAL-A12.5 and BAL-A19
70mm Bushfire Weepa
Narrow masonry. Bushfire compliance AS3959:2018 BAL-LOW, BAL-A12.5 & BAL-A19
ew Generation Bushfire Weepa
Bushfire compliance AS3959:2018 BAL-LOW, BAL-A12.5, BAL-A19, BAL-A29 & BAL-A40
Stainless Steel Weepa
Prestige look. Bushfire compliance AS3959:2018 BAL-LOW, BAL-A12.5, BAL-A19, BAL-A29, BAL-A40 & BAL-FZ
50mm Stainless Steel Weepa
Roman bricks. Bushfire compliance AS3959:2018 BAL-LOW, BAL-A12.5, BAL-A19, BAL-A29, BAL-A40 & BAL-FZ
BAL 40 Decking
Under BAL 40 requirements, decking must be made of non-combustible material and should not be spaced. Decking supports must either be non-combustible (steel or concrete) or be fully enclosed.
Gaps greater than 3mm in decking should be protected by corrosion resistant steel mesh with apertures less than 2mm in size.
We have a range of attractive decking materials that will meet the BAL 40 requirements including many of the fibre cement type panels such as Hardie Scyon Secura.
ModWood Flame Shield is an Australian product that is rated for up to BAL 40 settings. No other wood-based decking product has such a high rating.
ModWood is a wood plastic composite containing 50% wood fibres. ModWood features minimal contraction and expansion and requires no staining, oiling or painting. ModWood is made using sustainable timber sources.
It contains no formaldehydes and has proven itself time and time again over the past 16 years as an extremely effective fire protection barrier.
ModWood is available in Jarrah, Silver gum, Black bean and Sahara.
Doors and Windows
Openings into your home including doors, windows, skylights and ventilators are critical components in any system of defence against fire.
There are a number of options for ensuring these components in your new build meet BAL 40 requirements.
- You can use standard doors and windows provided they are protected by non-combustible bushfire shutters complying with AS3959:2009, or
- Use external doors and windows must comply with AS 1530.8.1 as tested from the outside, otherwise,
- Use a window and sliding door frames made of steel (including aluminium). Side-hung doors can include a solid 35mm timber section up to 400mm above the threshold. Glass must be 6mm toughened safety glass and any glass within 400mm of ground level must have metal screens with maximum 2mm apertures.
Hume has been making doors for Australian homes since 1953. The Hume Group is still a 100% Australian family-owned company and continues to create some of the best doors on the market.
Hume external doors come in an enormous variety of styles, most of which Hume can manufacture to BAL 40 standards.
Whether you’re looking for the timeless classic or a modern chic look you’ll find the door to your dreams in the Hume range.
The range of Hume doors that come in BAL 40 compliant formats includes:
- Linear 100
BAL40 Weatherguard frames are also available.
Under BAL 40 requirements any glazed penetrations into your roof must have a FRL (fire resistance level) of (-/30/-) and where the roof pitch is less than 18 degrees glazed penetrations must also be protected by ember proof metal screens.
VELUX have a range of exciting skylights that are rated for BAL 40.
VELUX are made in Australia and are covered by a 10 year warranty.
See the VELUX skylight range here.
Keylight is a European company that is producing exceptionally high quality skylights for Australian conditions.
Keylight offer electric, solar, manual, and fixed skylights that are rated for BAL 40 settings.
Offering superior performance; 80% heat block and 99% UV protection, Keylight skylights will add real value and light to any home.
Any roof penetration can provide a potential entry and ignition point for hot embers.
That’s why it’s important you check that that any ventilator you install meets the requirements for the appropriate BAL level.
The CSR EDMONDS Maestro BAL is a powerful, mechanically driven ventilator that will detect and remove heat and humidity from your roof space.
Smart technology means that it will automatically adjust fan speeds according to the conditions. Sturdy aluminium construction means it will last for many years.
CSIRO has assessed Maestro BAL as compliant with the fire rating requirements of AS3959-2009 up to BAL-40.
Its quiet economical operation and highly efficient design means that one Maestro BAL delivers the equivalent performance of 6 wind-driven vents.
Venta-a-Roof is another exciting energy-free way to ventilate your roof space. It works on the same principle as a traditional whirlybird but the vents are concealed under the ridges, hips, gables and cladding. 2.5 metres of Vent-a-Roof is the equivalent of one whirlybird ventilator. Vent-a-Roof is fully compliant up to BAL 40 rating.
Under BAL 40 requirements you may not install roof mounted evaporative coolers.
BAL 40 Gutters
To meet BAL 40 requirements gutters must be made from non-combustible materials. You must protect gutters and other openings with non-combustible ember guards.
Gutter guard requirements for the current Australian Standard (AS 3959-2018) are as follows:
The Australian Standard for building in a bushfire prone area (AS3959-2018) places only one restriction on gutter guard regardless of the Bushfire Attack Level (BAL). (see extract below)
“If installed, gutter and valley leaf guards shall be non-combustible”
Blue Mountain Mesh and Leaf Stopper are two superior products that meet BAL 40 requirements.
Both these steel mesh products come in a range of profiles to fit any roof cladding as well as to colour match with Colorbond colours.
Gutter Guard is an exciting foam gutter protection system that likewise meets BAL 40 requirements.
Karben Industries most popular gutter protection mesh has an aperture of 3mm x 4mm making it very effective for eliminating most leaves from your roof guttering system whilst allowing high volumes of water to pass through.
The aluminium gutter mesh has been CSIRO tested in accordance with AS 3959-2009 (construction of buildings in bushfire prone areas), aluminium gutter mesh is suitable for use as gutter guard in all Bushfire Attack Levels (BAL-12.5, BAL-19,BAL-29, BAL-40 & BAL-FZ)
Please be aware that this article offers guidance only.
You must seek professional advice and check your intended design complies with Council and code requirements before you go ahead with any building project.
Helpful BAL 40 Links and Information
Housing Industry Australia article on building in bushfire prone areas.
Rural Fire Services
This fact sheet clarifies the requirements of the NSW Rural Fire Service (NSW RFS) for combustible construction in Bush Fire Attack Level 40 and Flame Zone (BAL-40 and BAL-FZ) areas.
Bluescope Steel article on Bushfire Design Factsheet for Bushfire standard compliant steel roofing system
Helpful BAL FZ Downloads
Bluescope Steel fact sheet with details for bushfire-prone AS3959-2009 BAL-FZ sites