Author Topic: Approved document B 2006 diagram 7 and 8  (Read 3236 times)

Offline kurnal

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Approved document B 2006 diagram 7 and 8
« on: January 20, 2007, 11:01:09 AM »
I am very puzzled by the changes in the new ADB in respect of the design of commen escape routes from flats.

Diagram 7 and 8 and the the text seem to indicate changes from the old version and  from BS5588 part 1 1990.

Diagram 7a
In the past it was considered necessary to provide ventilation to the dead end portions of the common corridor and to the stair but not to the common lobby containing no risk. The new ADB dispenses with the ventilation to the dead  end common corridors and instead requires the lobby to be ventilated. Can this be right?

Diagram 8 a  b  c

If I have an ideal design with no dead ends I am required to ventilate the whole of the common corridor. But if I move the staircases to create dead end conditions I then only have to ventilate the dead end portions of the corridors? And then if I stick a T junction with a further dead end there is no requirement for ventilation there either?

Please tell me I have missed something or that it is a mistake. Have just completed a major project design review with  AOVs and OVs in compliance with 5588- are they in the wrong places now?

Offline wee brian

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Approved document B 2006 diagram 7 and 8
« Reply #1 on: January 21, 2007, 09:14:44 PM »
The ventilation is to protect the stair. It does this by creating a pressure differentila between the stair and the corrido. Only sections of corridor that open onto a stairway need ventilation.

Putting vents anywhere else is a waste of time.

Check out the research report on www.bre.co.uk/adb

Offline kurnal

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Approved document B 2006 diagram 7 and 8
« Reply #2 on: January 21, 2007, 09:35:28 PM »
Once again Wee B I am in your debt. Looks like I've got some bedtime reading to do. Printer is working overtime.
Still surprised by the outcome though.
Thanks
Alan