Numbers of Fire Wardens

[Fairway123]

Hello FireNet

Does anyone know of anywhere where numbers of fire wardens are actually documented? We have looked into increasing the occupancy of the top floor of one of our buildings (10th floor) and have approached a fire engineer. He was unable to come up with a physical engineered solution (such as extra staircase etc). But did say that the increase could be allowed through management procedures. He then went on to specify a 1:20 ratio of fire wardens to occupants. I personally think that this is excessive but can't find where he plucked the number from. Building is sprinklered with AFD and 24 hr security, and there are 2 escape staircases within 45 seconds of the exit. We would be having 200 people (potentially external and unfamiliar with the building) in an auditorium which would be a single room, so this would need 10 fire wardens.

Based upon a risk assessment I'd suggest 4/5 with additional if there were people with mobility/sensory issues. Before I challenged it I felt it best to seek the wisdom of the community.

Anyone have any thoughts, or have an idea where the 1:20 ratio came from?

Many thanks

F123

[colin todd]

Air so thin that it would not support fire development.

[wee brian]

Sentences that start "based on a risk assessment" usually end with a bunch of made up numbers....

If you cant get the escape routes to work using something like BS 9999 then you have a problem. I wouldn't support a proposal to increase numbers based on fire wardens - what do you think they would do?

Maybe you could get them to shout - "run for your lives, we're all going to die" that might improve the RSET 

[JT]

Sort of a relevant video/slight tangent. Not commenting on fire wardens but interesting one to consider.

http://www.thunderheadeng.com/2017/05/d1-09-brown/?utm_content=buffere6fb5&utm_medium=social&utm_source=linkedin.com&utm_campaign=buffer

[SeaBass]

I think that you probably need to approach another FS professional. You can?t increase occupancy numbers through better FS management alone.  The maximum occupancy numbers are based on the available escape width, the number of escapes (if you have two, then one must be discounted, assumed rendered inaccessible due to fire)   the evacuation strategy employed the building, ceiling heights, the category of fire detection and alarm system and provision of automatic suppression. As you already have sprinklers, and the AFD is quite probably a better classification than is required, I suspect that your options are very limited.

Also bear in mind that if a fire engineer suggests a solution that deviates from national guidance, but which can?t be supported with calculations or other hard evidence, then there is a good chance that a fire risk assessor or an inspecting officer would not accept it, even if a building control officer did. 
     

[Fairway123]

Thanks for the responses. The pathfinder information was particularly interesting.

My initial thoughts were that the engineer was having a bit of a nightmare by suggesting it. It certainly looks like he as plucked the 1:20 ratio from thin air.

 Having taken a proper look at the calculations, it is actually possible to meet the occupancy level as a B1 risk profile by allowing for 'additional measures' on ceiling height and AFD.  This gives us what we need and a margin of safety of 8%. So I need to query this with him (probably his supervisor).

Looks like we may need to speak to another engineer.