On 22/01/13 4:57 PM, Russell Coker wrote:
By "tanker" do you mean fire truck? If so then presumably the truck is designed to go into unsafe situations while a sensible person would cut down trees that are too close to their house and take other measures to reduce the risk. Yep, and I did say garden design would be part of making a house fire resistant, which would cover cutting down trees, etc. If you had a house made of solid relatively airtight concrete including a concrete roof with solid shutters then it doesn't seem that you would need any water protection system. If you had a house of a typical suburban design then it seems that no reasonable amount of water would save it unless you also have water inside the roof cavity to stop embers that get through gaps in the tiles. The water would limit damage to the concrete or other structural materials, but the use of such materials would minimise any extra protection needed.
It doesn't seem like adding water will be guaranteed to save a house that wasn't already fairly safe without the water.
Do bushfires get hot enough to ignite aluminium? A quick google suggests that aluminium ignites at about 2000C which combined with being a great reflector of light and even better for infra-red means that it's probably going to resist anything a bushfire can do from a distance. So aluminium shutters should do.
They certainly get hot enough to _melt_ aluminium. A school friend had a "souvenir" from being burnt out during Ash Wednesday. It looked like a bit of modern sculpture, like something poured out and painted silver. What it was, in fact, was the remains of the engine block from their lawnmower. The heat from the fire had turned the engine block into a pool of molten metal. -- 73 de Tony VK3JED http://vkradio.com