What are the benifits of a possitive pressure differential system? with regards to relaxed passive fire protected (i.e. protected lobby doors not needed ect.) There is a limited amount of information in ADB and BS.9999, what reference do you recommend?

You naughty boy Ryan :angry: this is not a question suited for this forum. I have only been involved in one pressurised staircase situation many moons ago and one considerations they never took into account was somebody would light a fire in the staircase enclosure. As for the guidance documents you referred too I know BS 9999 is slated by many and the best place for this question is on the Fire Net forum when it comes back online.

I shall meet you there soon

Tom :wub:

Thanks Tom ;) , see you there