Updated October 2026
Composite decking and bushfire ratings (BAL)
Composite decking can only go where the site's BAL and the board's own fire test allow it. BAL-40 and BAL-FZ need non-combustible decking, which standard composite isn't. For BAL-12.5 to BAL-29, ask for the board's AS 1530.8.1 test report.
1. Find your BAL
The Bushfire Attack Level is set for the site, usually on the building permit or a BAL assessment: BAL-LOW, 12.5, 19, 29, 40 or FZ (flame zone).
2. What the deck needs
| BAL | Deck |
|---|---|
| BAL-LOW | No bushfire construction requirements. |
| BAL-12.5 to 29 | AS 3959 sets the rules; they vary with the level and how close the deck is to the house. Composite needs a fire test (AS 1530.8.1) showing it meets the level. |
| BAL-40 | Non-combustible decking, enclosed or non-combustible subfloor. |
| BAL-FZ | Non-combustible decking with no gaps, enclosed or non-combustible subfloor. |
3. Ask for the right report
The AS 1530.8.1 report must cover the exact board profile you're buying. Your building surveyor makes the final call.
Questions
Can I use composite decking in BAL-29?
Only if that specific board has been tested to AS 1530.8.1 and achieved BAL-29. Check the report names your profile.
Is composite allowed in BAL-40?
Standard composite isn't; BAL-40 needs non-combustible decking such as aluminium systems.
Who decides if my deck complies?
Your building surveyor, from the site BAL and the product's test evidence.
Pricing a deck? Count the boards, see the price list or get free samples.