Life safety system cabling inside smoke extract shaft

I can see what makes you feel uncomfortable about it

If this is a smoke shaft protecting a fire fighting shaft, then you should excluding non-fire related services from smoke shafts, as BS 9991 - to me the requirement is to have the cabling inside the protected shaft, not the smoke shaft


They are smoke shafts not risers essentially (although they are attractive places to install cabling for some)


Post Grenfell, you need to be absolutely 100% certain  about what is specified and where - go back to the designers and get an absolute clarity on what they have designed - and get that in writing (presumably you have a TQ or RFI procedure for this) - don't guess


regards


OMS

Thanks for the response.

You are right, while they sound confident over the phone, hopefully they might change their view when I request clarification in writing.

Inevitably such work will be subject to a building control application which normally requires the applicant to specify how fire safety is to be met. That is usually via ADB, BS9999 2017 or via a fire engineered approach. We commonly use 9999 where possible at it provides for a slightly more flexible design. That document makes it clear that smoke vents for firefighting shafts should not have any services within other than those that are directly related to the operation of the smoke shaft. Even if the smoke shaft is for other than firefighting purposes, such as part of a smoke control system for protected lobbies and corridors, the same restriction applies.

Common sense would tell you that because these smoke vent systems are often subject to careful modelling using computational fluid dynamics methods to confirm appropriate operation, sticking services in the vent shafts ain’t clever!