Radial plumbing & fire stopping near the manifold

[Dunc]

Just need a sanity check please:

Fire stopping is required for service penetrations between separating floors (Scotland, Domestic Tech Handbook 2025, 2.2.9, p88).  Exceptions are listed which seem to cover most of the requirements for single domestic dwellings (exerpt below).

However with radial plumbing I'll end up with 21 plastic pipes of 15mm diameter from the manifolds heading up into the ceiling void before dispersing to outlets. Of course these pipes will basically be in 1 group in order to connect to the manifods. The forum is full of examples of mainfold based plumbing, so have I missed something in terms of the fire stopping, or the exemption?

 

Fire stopping of the following services passing through a separating wall or separating floor need not be provided for:
• a pipe or a cable with a bore, or diameter, of not more than 40 mm, or
• not more than four 40 mm diameter pipes or cables that are at least 40 mm apart and at least 100 mm from any other pipe, or
• more than four 40 mm diameter pipes or cables that are at least 100 mm apart, or
• a pipe which has a bore of not more than 160 mm and is of iron, steel or copper, or of a material capable of withstanding 800 ºC without allowing flames or hot material to pass through the wall of the pipe, or
• a branch pipe of a bore of not more than 110 mm connected to a vertical drainage or water service pipe, constructed from aluminium, aluminium alloy, or uPVC to BS 4514: 2001.

[kandgmitchell]

I'm not conversant with the Scottish Regs but I would have thought your installation of 15mm pipes falls under the exemption stated in item 1 i.e

 

a pipe or a cable with a bore, or diameter of not more than 40mm 

 

There appears to be no restriction on the number and of such pipes unlike the larger 40mm and above pipes