What stage of an incident should ventilation begin?

[scotthall]

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thanks

[kurnal]

Thats a hard question.
Depends on the incident, is it a room or a building, domestic or warehouse,  and the state of development of the fire, the signs and symptoms on arrival. And the reason for the ventilation- may be to assist search and rescue, or to assist location of fire, or to mitigate damage, or to improve conditions for firefighting etc.

The Fire Service manuals are what you need to read and the booklets on tactical ventilation.
 
The general guidance would be not to ventilate until you have the fire surrounded  with all openings covered and established that no-one will be placed at risk if the ventilation causes an increase in the growth of the fire- or backdraft.

[messy]

Scotthall

Have a look here at Paul Grimwood's website

Beware, much of this may not be UKFRS procedures, but you'll have difficulty finding any more detailed info on the subject anywhere else on the web (unless anyone knows better??!)

http://www.firetactics.com/tacticalventilation.htm