What is Bush Fire Protection?
Bush fire Protection is the protection of buildings, as specified in the Australian Standard AS3959-2009 "Construction of buildings in bushfire-prone areas", against burning embers, radiant heat or flame generated by a bushfire.
2. When is Bush Fire Protection required?
Bush fire protection under AS3959-2009 is required on sites where the Bushfire Attack Level (BAL) has been determined as one of the six levels of risk;
1. BAL - Low
2. BAL - 12.5 (protection from ember attack and radiant heat up to and including 12.5kW/m²)
3. BAL - 19 (protection from ember attack and radiant heat greater than 12.5kW/m² up to and including 19 kW/m²)
4. BAL - 29 (protection from ember attack and radiant heat greater than 19 kW/m² up to and including 29 kW/m²)
5. BAL - 40 (protection from ember attack, increased likelihood of flame contact and radiant heat greater than 29kW/m² up to and including 40 kW/m²)
6. BAL - FZ (protection from flame contact, together with ember attack and radiant heat of more than 40 kW/m²)
3. How can Crimsafe resist attack from burning embers?
The Australian Standard AS3959-2009 requires screening of openings to be made of corrosion resistant steel, with an aperture size that will not allow a circular probe of 2mm diameter to pass through. Crimsafe 304 grade, 0.9mm stainless steel mesh has an aperture size of 1.5mm x 1.5mm and therefore automatically complies with the standard.
4. Can Crimsafe be used in all BAL's?
In general Crimsafe screens can be used in all Bushfire Attack Level's on all windows, hinged, bi-folding and sliding doors.
The only exception is BAL-FZ where Crimsafe screens could only be used on a window system that has been tested to a Fire Rating Level of -/30/- OR complies with AS1530.8.2 when tested from the outside.
5. Where else in a building can Crimsafe screens be used for Bushfire Protection?
Apart from windows and doors, Crimsafe can also be used to protect decks / patio enclosures, evaporative cooling units, skylights, gable & roof vents, weep holes, enclosing subfloor areas and for use as a gutter and roof valley leaf guard.
6. How do you install Crimsafe for Bush Fire Protection applications?
1. Depending on the BAL either the opening section of the window or the full opening is required to be screened. Refer to the Construction detail for each BAL as per AS3959-2009.
2. Screens must be installed in accordance with the Australian Standard AS5040-2003 "Installation of security screen doors and window grilles" OR as per the Crimsafe installation manual.
3. Metal fixings must be used.
NOTE: Even though the screens may be specified as a Bushfire screen, as a default they will be providing a high level of security screening, solar shading & insect resistance. However, in the case of a fire they will provide protection from ember attack, reduction of radiant heat and protection of the glazing from the impact of flying debris. This should be considered when specifying and installing the screens.