BAL building materials: decking, windows, doors and cladding
The materials you can use on a house in a bushfire-prone area depend on its BAL. At BAL-12.5 and BAL-19, most standard products work with ember protection added. From BAL-29, glass, frames, decking and cladding have to resist more heat, and at BAL-40 and BAL-FZ many elements need to be tested systems. Here's what that means for each.
Don't know your level yet? Check your likely BAL first, because it decides which products are even on the table.
A BAL determines which construction requirements apply to the building. Your building surveyor or an accredited bushfire practitioner can tell you what they are.
Checking a product before you buy
- Confirm your BAL. Use an indicative result to plan, but buy against the formal BAL your building surveyor accepts.
- Ask for the test evidence. Get the manufacturer's current bushfire test report for the exact product and fixing system, and check the level it covers.
- Check the installation. The rating applies to the product installed as tested.
- Run it past your building surveyor before you order, especially at BAL-40 and BAL-FZ.
For what each level involves overall, see BAL levels explained and the level guides: BAL-29, BAL-40 and BAL-FZ.
BAL Buddy gives an indicative Bushfire Attack Level (BAL) only. It isn't a determination under any Act, and no council or building surveyor has to accept it. For a BAL you can rely on, use an accredited bushfire practitioner.
Questions people ask
What decking can I use at BAL 40?
Non-combustible materials or a decking system tested for BAL-40. Timber decking generally isn't an option at this level.
What are the BAL 29 window requirements?
Toughened glass in metal, bushfire-resisting timber or metal-reinforced uPVC frames, with metal mesh screens on openable parts, or bushfire shutters instead.
Do I need shutters at BAL-FZ?
Not necessarily, but they're common. Windows and glazed doors at BAL-FZ need to be tested for flame contact or fire-resistance rated, and tested shutters are one way to meet that.
Is composite decking BAL rated?
Some is and some isn't. Ask the manufacturer for the current bushfire test report for the exact board and fixings, and check it covers your BAL.
Can I use timber cladding at BAL 29?
Sometimes. Bushfire-resisting timbers and some higher-density species are allowed, with limits near the ground and decks. Check with your timber supplier and building surveyor.