What Your BAL Rating Means for Gutter Guard and Ember Guard

If you live near bush in the Illawarra, Southern Highlands or South Coast, your BAL rating affects which gutter guard and ember guard can go on your home. It comes up when building, renovating or choosing gutter protection. Here is what a BAL rating means in plain English, and how it decides the products that go on your roof.
What is a BAL rating?
BAL stands for Bushfire Attack Level. It rates how exposed a building is to embers, radiant heat and flame in a bushfire. The ratings come from Australian Standard AS 3959-2018, Construction of buildings in bushfire-prone areas. New builds and renovations on bush fire prone land are given a BAL through a bushfire assessment.
The six BAL levels
- BAL-LOW: very low risk. No specific construction requirements.
- BAL-12.5: risk mainly from embers and burning debris.
- BAL-19: increasing ember attack and burning debris, plus some radiant heat.
- BAL-29: higher ember attack and radiant heat.
- BAL-40: high radiant heat, with flames possible against the building.
- BAL-FZ (Flame Zone): direct exposure to flames from the fire front.
How to check if your land is bush fire prone
You can check whether your property is mapped as bush fire prone land on the NSW Planning Portal, or ask your council. If you are building or renovating, the bushfire assessment for your project sets your BAL, and your certifier has the final say on what is required.
Gutter guard requirements by BAL rating
AS 3959-2018 requires gutter and valley leaf guards on homes in bushfire-prone areas to be non-combustible. Plastic mesh is not tested to the bushfire standard. Karben aluminium gutter guard, which Illawarra Maintenance Group installs, is CSIRO tested with a Spread of Flame Index of 0 under AS/NZS 1530.3, and is suitable at every BAL. Test documents can be emailed to your builder or certifier.
Ember guard is a different product
Gutter guard covers gutters and valleys. Ember guard covers openings into the building, such as vents, weep holes and gaps into the roof space, and needs holes no bigger than 2 mm. The material allowed depends on your BAL:
- BAL-LOW: no ember guard required.
- BAL-12.5, BAL-19 and BAL-29: 1.9 mm aluminium ember guard is suitable.
- BAL-40 and BAL-FZ: aluminium is not suitable. IMG supplies and fits Karben 1.9 mm stainless steel ember guard.
Choosing the right Karben mesh
IMG fits Karben 3.5 mm standard, 3.5 mm heavy duty and 1.9 mm woven aluminium mesh, plus 1.9 mm stainless steel. The right one depends on your trees, your roof and your BAL. Our Karben gutter guard guide covers mesh choice in more detail.
Gutter guard is one part of your bushfire plan
Metal gutter guard stops leaves building up where embers land, but it does not make a home bushfire proof. Keep the ground around the house clear, trim trees back from the roof, seal gaps into the roof space and follow the NSW RFS advice on preparing your property. Our bushfire season gutter checklist is a good place to start.
Frequently asked questions
What gutter guard is best for BAL-40 or BAL-FZ?
Karben aluminium gutter guard is suitable at every BAL. For ember guard at BAL-40 and BAL-FZ, IMG fits Karben 1.9 mm stainless steel.
Can I use plastic gutter guard in a bushfire area?
AS 3959-2018 requires gutter and valley leaf guards in bushfire-prone areas to be non-combustible, so metal mesh is the right choice.
Where do I find my BAL?
If your home has been through a bushfire assessment, the BAL is in that report. You can check whether your land is bush fire prone on the NSW Planning Portal or with your council.
Get the right gutter guard for your BAL
IMG comes out, measures your roof properly and gives you a free written quote, with the right Karben product for your rating. Product carries a 15-year warranty and workmanship a 20-year warranty. Read more on our bushfire and ember guard page, or see the areas we cover on our gutter guard installation page.
Call 0411 389 184 or request a free quote and we will be in touch.