Hi all,
This is probably a basic question which I should know but is something which I have recently been confused about due to a number of premises I have recently visited.
My question is should electrical risers be fire stopped at each level within a building so there is no free run of smoke / flame between the compartment floors?
Until recently it was my understanding that electrical risers should be adeqautely fire stopped at each compartment level. However, recently I have visited a number of multi-storey residential premises where this has not been the case. All have adeqaute FD30s fire doors leading from the risers into the common areas and the shaft itself appears to have been constructed with appropriate fire resistant materials. I know this may be a straightforward question and I understand that Approved Document B diagram 31 does not show that a protected shaft requires fire stopping at each level but I just wanted to check with your expert opinion.
Also, I if may note that from the risers there were vents leading from the riser into the common area. I can only think there are vents within the risers leading into the common area because of the gas supply within, which inline with ADB require venting. However, due to the electrics within these risers surely the vents would compromise the required compartmentation of the shaft.
This was not picked up in previous risk assessments, by the building control officer of by the local fire service during their recent visit so I am wondering if it is just me missing something glaringly obvious.
If anyone could help me with this it would be much apprecaited