Dam Buster rain heads look like a normal rain head but instead of just being a metal box with a down pipe in the bottom, all models incorporate a unique internal weir, combined with a primary overflow chute downstream of the weir and hidden behind the front facade. There is also a separate box gutter seal to prevent leaks and finally, a secondary overflow mechanism on the front face. See the cutaway diagram on the right.
If the down pipe ever blocks or the volume of water discharging from the box gutter over whelms the normal operation of the rain head, water simply discharges over the weir and is disposed of safely "to atmosphere" outside the building as required by Australian Standards. In absolutely extreme conditions, the secondary front overflow device of the Dam Buster may also operate as a further precaution to protect the building and contents.
This unique design allows the Dam Buster range to safely cope with enormous volumes of water during normal operation and without any risk of back flooding or over topping of the box gutter - both extremely common causes of catastrophic internal building flooding and insurance claims.
Because of their unique design, all Dam Busters also provide full AS3500.3 compliance in the case of back flow from the storm water system itself coming back into the rain head.
The whole Dam Buster range has been subjected to comprehensive independent testing by the best Hydraulic Engineers in Australia and all models are certified to handle substantial flows during normal operation plus will also overflow at the rate of at least 16 litres per second. They will keep efficiently working and doing their job when other rainheads have given up and flooded the building.
All Dam Buster models also fully meet the Deemed to Satisfy requirements of the NCC (National Construction Code) and do not require any form of Performance Solution.