Flashover and Backdraft

[GregoreK82]

Hi, if wrong section please remove. 

Just wondering if anyone of more experienced colleagues can explain in his own words definitions of flashover and backdraft? Thanks in advance 

[OscarTango]

Flashover. When a fire in a room becomes a room on fire. Everything in the room has become available fuel and what can burn, will burn. It needs to be ventilated to happen.

If it doesn't have a good air supply, the fire gases and pyrolizing material stay in the compartment and fill up the space slowly mixing, but with no air it moves out of it's flammable range. It's still very hot. When you open a door or window say, the gases nearest to it suddenly have the air they need to burn and catch fire violently and out of the direction of the door or window (it chases the air essentially). That's a backdraught. 

Hope that helps

[Hmckay91]

The Small Scale Fire Behavior Prop Demonstration may help clarify and solidify the situation.

[GregoreK82]

Massive thanks for both of you ?