In order to make sure that your house is in a better position to handle the bushfire attack and its effects, there are multiple requirements for construction as per the standard, which depends on the level of bushfire risk in the area. The more your area is at the risk of a bushfire attack, the direr it is that you meet these requirements. One thing that is common to all lists of requirements in bushfire-prone areas is installing an ember mesh guard.
An ember guard is known as “a cover inserted in or over an opening or cavity to prevent the entry of burning embers” as defined by AS3959–2009.
Composition of an Ember Guard
Ember guards should have a hole size no bigger than 2mm and made up of a perforated or a mesh. In addition to this, they should be made from materials that are non-combustible. Your BAL (Bushfire Attack Level) tells you the level of risk you’re at, and hence the materials you should use.
If the BAL of your residential area is 12.5, 19, or 29, you can get ember guards made up of bronze, aluminum, or corrosion-resistant steel. However, you will be required to make an ember guard of bronze or corrosion-resistant steel with a BAL of 40 or FZ.
Importance of Ember Guards
More than eighty-five percent of houses that become victims of bushfires do not catch fire by coming into contact with the bushfire directly, but due to the embers that are windborne. This attack caused by the embers can be fatal to your house, as it can not only set fire to other fuel sources near you but also cause an internal house fire via embers that get through the house by gaps that are 3mm small.
This threat of burning your house due to such embers can be easily prevented by installing ember guards.
The Need For Ember Guards
You might need to place ember guards in different places of your house depending upon what your BAL rating is. Here are those places mentioned along with information on whether a mesh guard is required there or not (as per AS3959-2009):
1. Openings in Roof Ventilation: From BAL 12.5-FZ, all houses are required to have amber guards in the openings
2. 3mm+ Gaps in Sheet Roofs: From BAL 12.5-40, all houses are required to get an ember guard on the wall line as well as the hips, valleys, and ridges of the sheet roof. For BAL FZ however, such gaps must be filled and sealed properly with other materials.
3. Roof ventilator, vent pipe, and vented roof light openings: An ember guard has required for BAL 12.5-40 areas while the openings need to be properly sealed with other materials in BAL FZ areas.
4. Evaporative cooling units: Ember guards required in BAL 12.5-29 areas and not applicable in BAL 40 and FZ areas.
5. 3mm+ openings in eaves ventilation: Ember guards required in BAL 12.5-40 areas while proper sealants to be used in BAL FZ areas.
6. Roof light glazing pitch < 18 degrees to horizontal: BAL 12.5 and 19 areas do not require ember guards here. However, BAL 29 and 40 do. As far as BAL FZ areas are concerned, the roof lights do not need ember guards but are required to comply with other conditions.
Gutter Guard King Ember Guard Gutter Mesh
Gutter Guard King’s 2mm gutter mesh in aluminum is compliant with the ember guard standards. It can conveniently be installed as ember guards in order to meet the AS3959-2009 requirement when building new homes in areas rated BAL (12.5 – FZ).