BS 9999 / ADB - Discounting of Stair rule

[ST1878]

Has anyone come across the apparent anomoly for the discounting of stairs in sprinklered buildings yet?
BS 9999 para 18.3.2 states "the stair discounting process DOES NOT APPLY to a building fitted with a sprinkler system".
This appears to be at odds with the earlier DD 9999 para 8.8.3.2, and the current ADB para 4.20 which state "stair discounting ALSO APPLIES to a building fitted with a sprinkler system, unless the staircase is lobbied or pressurised".

We have requested clarification from the relevant bodies, but have yet to receive an explanation to the difference, and we have now had proposals from an AI referring directly to the para in the new BS.

[wee brian]

I'm not sure if that counts as an anomoly, The are different codes - they will say different things.

[jokar]

Sprinklers are invoke and the answer to all our prayers.  As above, different code, different standard, its out there for use and people will use it.

[colin todd]

if the nat west tower is sprinklered it would probably only need one 530mm exit for compliance with BS 9999.

[Galeon]

It is

[wee brian]

You would still need to discount a storey exit wouldnt you?

[Davo]

What does BS 7974 have to say on this dilemma?

I for one would not want a designer to put one less stair in because you don't need to discount (IMO)

Davo

[wee brian]

Well if you need two storey exits then I think you will need a stair next to it. Iether that or issue parachutes.

[jokar]

As we are all aware fire safety is joined up thinking and stair discounting is not a subject of its own, it also includes travel distance and numbers of people.  What 9999 does is limit in some circumstances the numbers of exits and stairs that are needed and substantially in some areas.

[colin todd]

Parachutes, brian................ HMMMMMMMMMM Could that be a new business opportunity?

[wee brian]

No mate - Fire evac parachutes have already been patented. They tried flogging them after 9/11

[colin todd]

Ah Brian, it just goes to show there is nothing new in this world. No wonder, I/Os keep rediscovering what we knew 30 years ago. Should I just keep my money in intumescent strip manufacturers then?

[Thomas Brookes]

Evacuchute. Do you think these would be suitable for old peoples homes





http://www.evacuchute.com/products_build_civilian.html

[colin todd]

Yes it would give the wrinklies the thrill of their (imminently ending) life.

[Thomas Brookes]

I would love to see someone write that in to a risk assessment.

Imagine the look on the IO face when he does an audit.