Bal Rating – What do they mean?
How they can affect your window purchase decision.
Bush-Fire Attack Levels (BAL) ratings were introduced into the National Construction Code (NCC) previously call the Building code of Australia in May of 2010 after the devastating Black Saturday bush fires in February 2009. There are 6 levels within the rating shown below and most window and door types are adequate to achieve up to a BAL-29 rating with metal fly-screens including our uPVC Double Glazed Windows. Is is worthy of noting that the PVC product that our windows and doors are made from is self extinguishing and will only burn when a flame is directly on the profile therefore making it a great choice for areas rated to BAL-29.
Read about a home constructed from PVC Weatherboard, Windows and Decking that survived the 2009 Black Saturday Bushfire in Marysville. Click here to read more.
Bushfire Attack Levels (BAL) Ratings
- BAL – Low – There is insufficient risk to warrant specific construction requirements
- BAL – 12.5 – Ember attack
- BAL – 19 – Increasing levels of ember attack and burning debris ignited by wind-borne embers together with increasing heat flux between 12.5 and 19 kW m2
- BAL – 29 – Increasing levels of ember attack and burning debris ignited by wind-borne embers together with increasing heat flux between 19 and 29 kW m2
- BAL – 40 – 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
- BAL- FZ (Flame Zone) – Direct exposure to flames from fire front in addition to heat flux and ember attack.
Whilst uPVC Windows and Doors can not be used in a BAL-40 or BAL-FZ rated area, not many products in today’s market can. Steel and Aluminium are about the only products that can be used in a BAL-40 Rated area and to achieve Flame Zone compliance windows will have to be completely protected by a Bushfire Shutter compliant to Australian Standard AS3959. Shutters and Steel windows can be very cost prohibitive and obtaining a Bushfire assessment from an independent company such as Ecotide may help to reduce the determined BAL rating and save money during construction in the long run.
Contact one of our consultants to talk about how are Double glazed uPVC windows can be used in you Bushfire rated home.