We have an electrical riser in a 5 story building which from a fire perspective is classed as one compartment as it is an open shaft effectively between each floor with fire doors leading to office floors on each level needed for Maintenence engineer access. As the riser is an open shaft effetively is there a need for each level to be completly fire stopped therefore creating a compartment on each level and if that were to be the case is there a need for a Fire detection device in each compartment?.

I found myself in a similar situation in a newly built public entertainment complex a few years back. I wanted to see automatic detection in these spaces and after consulting the L.A. Building Control and Fire Brigade,so indeed did they.

Others have already suggested some points, there are a multitude of things, many of which I probably can’t think of at the moment. I can just offer some advice on the electrical side, which may or may not be what you actually want or of use. Obviously the electrical installation should conform to legislation, one of the ways HSE suggest that this can be achieved, informally, but, via a note in the introduction is by the fixed electrical installation being installed to be compliant with BS7671:2008, Requirements for Electrical Installations, IEE Wiring Regulations Seventeenth Edition. There in, Section 527 Selection and erection of wiring systems to minimize the spread of fire has the relevant guidance with respect to the sealing of such electrical risers. There has been previous similar guidance in previous editions, but I don’t have them to hand now. This section is just over 1 side of A4. You could also refer to: IEE Guidance Note 4: Protection Against Fire, 5th Edition (GN4) I cannot publish extracts here for fear of infringing copyright, but I do have a copy of both these documents on my desk at the moment. BS7671, Section 527.1 refers to precautions within a fire segregated compartment. This refers to wiring materials that are non-flame propagating and how these are utilised. As you have a single compartment, if the wiring systems installed there in comply with the relevant standards for being non-flame propagating then from this standard there are no requirements for any sealing or detection. BS7671, Section 527.2 refers to sealing of wiring system penetrations through building structural elements. Basically any cable duct which is non flame propagating passing through building elements must be fire sealed to the same level as the building structure it penetrates if over 710mm square in internal area, that is for example 25mm outside diameter metal conduit does not need sealing, 32mm outside diameter metal conduit does. 25mm x 25mm steel trunking (not common) does not need sealing, however 50mm x 50mm does (more common), both of these are small sizes dwarfed by your riser I suspect! GN4 Chapter 6 refers to the recommendations with respect to “Measures to minimise the spread of fire”. HTH Paul