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

[Dunc]

Ah. I took that first point to refer to a single, isolated pipe (although I realise "isolated" isn't defined). Perhaps I was being distracted by tge "not more than 4" in the second bullet.

 

Just concerned that effectively with the manifolds I'll end up with a slot at least pipe diameter (15mm) x 325mm, plus clearance, which may not be acceptable to BC.

[JohnMo]

11 hours ago, Dunc said:

radial plumbing I'll end up with 21 plastic pipes of 15mm diameter from the manifolds heading up into the ceiling void

I would simplify.

 

Why not do 2 up and 2 downstairs (1 each hot and cold). Then a single 15mm between each manifold. 

 

To make it simple, we do one 15mm to each wet room from each manifold, then branch from there in the wet room.

[Nickfromwales]

1 hour ago, JohnMo said:

I would simplify.

 

Why not do 2 up and 2 downstairs (1 each hot and cold). Then a single 15mm between each manifold. 

 

To make it simple, we do one 15mm to each wet room from each manifold, then branch from there in the wet room.

Too much kit spread all over the house. 
 

Radial methodology is supposed to do away with such complication.

[Nickfromwales]

2 hours ago, Dunc said:

Ah. I took that first point to refer to a single, isolated pipe (although I realise "isolated" isn't defined). Perhaps I was being distracted by tge "not more than 4" in the second bullet.

 

Just concerned that effectively with the manifolds I'll end up with a slot at least pipe diameter (15mm) x 325mm, plus clearance, which may not be acceptable to BC.

There are times when folk cant see the woods for the trees. 
 

Just use copper off the manifolds, then a hep2o connector to concert back to plastic once through the fire wall.

 

”Simples!”   

[JohnMo]

12 minutes ago, Nickfromwales said:

Too much kit spread all over the house. 
 

Radial methodology is supposed to do away with such complication.

Still have the same amount of manifold outlets, without the faff of punching loads of holes through between floors. Two holes job done. If you 21 pipes between the upper and lower floor you already have way too much complexity. So saying 21 pipes between floors is not complex, seems a stretch

[Nickfromwales]

3 minutes ago, JohnMo said:

Still have the same amount of manifold outlets, without the faff of punching loads of holes through between floors. Two holes job done. If you 21 pipes between the upper and lower floor you already have way too much complexity. So saying 21 pipes between floors is not complex, seems a stretch

Then I’ve been very successfully “stretching” myself for the last couple of decades.

 

1). Drill hole. 

2). Insert pipe through hole. 
3). See 1. 
4). Count to 21 and stop.

 

🤷‍♂️🙃

[JohnMo]

Just now, Nickfromwales said:

1). Drill hole. 

2). Insert pipe through hole. 
3). See 1. 

Count to 2, have a cuppa or go to pub while other person continues drilling the other 19 holes. Then if surface mounted the plasterer say what numbty put all this pipes here 

[Iceverge]

10mm should be fine for everything other than baths and showers. 

 

15mm to the kitchen sink if you want to recreate a waterpark. 10mm is fine otherwise in my experience