Supporting pipes under floorboards + insulation

[sailesh]

Hi folks - nice to join this forum and I wish I'd done so earlier. Some urgent advice needed please..

Our plumber has had to repipe the central heating in our Victorian house because the existing system was single pipe. He has done this using plastic pipe and push fittings. The first time we turned the heating on, the ground floor system leaked into the underfloor void at a sagging 90 degree joint that sits in the middle of circa 4 metres of unsupported pipe. I've attached a video which shows exactly what this looks like..

I'm not convinced by his argument that the pipes don't need any support and only the fitting is at fault, so to save me the roundabout discussion could anyone please point me to the relevant guidance that defines how much sag is acceptable and what the support criteria is or isn't for 22mm plastic pipe?

 

[ShaunCorbs]

Needs clips every meter and lagging

 

[gmartine]

Hi folks - nice to join this forum and I wish I'd done so earlier. Some urgent advice needed please..

Our plumber has had to repipe the central heating in our Victorian house because the existing system was single pipe. He has done this using plastic pipe and push fittings. The first time we turned the heating on, the ground floor system leaked into the underfloor void at a sagging 90 degree joint that sits in the middle of circa 4 metres of unsupported pipe. I've attached a video which shows exactly what this looks like..

I'm not convinced by his argument that the pipes d5on't need any support and only the fitting is at fault, so to save me the roundabout discussion could anyone please point me to the relevant guidance that defines how much sag is acceptable and what the support criteria is or isn't for 22mm plastic pipe?

No sag is acceptable the lazy scrot, should be clipped every 0.5m minimum for horizontal run in 22mm.

See page 19.

https://www.johnguest.com/wp-content/uploads/2019/08/RWC-JG-Speedfit-Technical-Specs-Guide.pdf

 

[exedon2]

Polypipe exactly the same 500mm horizontal 15mm every 300mm

 

[gmartine]

...and btw the fitting isn't necessary leaking because it's faulty. It's more likely to be leaking because the pipe isn't properly seated and or the fitting is under stress because of the lack of support.

 

[sailesh]

Needs clips every meter and lagging

agreed about the lagging -

No sag is acceptable the lazy scrot, should be clipped every 0.5m minimum for horizontal run in 22mm.

See page 19.

https://www.johnguest.com/wp-content/uploads/2019/08/RWC-JG-Speedfit-Technical-Specs-Guide.pdf

Perfect, thanks! I’m using a registered gas engineer so never expected this

Besides the manufacturer‘s spec, what / where are the building or other regs that installers should be following?

also, from a trade perspective, what is a customer’s recourse when work doesn’t meet regs or standard? It strikes me that a lot of work could / should be checked by an independent, or at least recorded as proof of continuing competence.
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...and btw the fitting isn't necessary leaking because it's faulty. It's more likely to be leaking because the pipe isn't properly seated and or the fitting is under stress because of the lack of support.

totally agreed, and also, no idea how my plumber expects to be able to drain the ground floor.

it gets worse really as I removed the floorboards and can see that other (15mm) pipe is only supported by a partition wall and - no kidding - an electric cable.. see attached pic.

 

[exedon2]

No pipe lagging under a floor void big no needs insulating

 

[sailesh]

No pipe lagging under a floor void big no needs insulating

sorry, do you mean it does or does not?

The pipes are feeding three radiators, each 1.5kW, so I can see the case that at max demand the flow is high enough that piping heat loss is relatively low, but at lower flow does insulation make that much difference?

 

[exedon2]

Have a look at building regulations part L insulation is a necessity needed for thermal efficiency and for frost protection

 

[gmartine]

British Standards BS6700:2006
Design, installation, testing and maintenance of services supplying water for domestic use within buildings and their curtilages.

Maximum spacing of fixing for internal piping

PB or PEX pipe

clip spacing = horizontal/vertical

Up to 16mm diameter = 0.3m/0.5m
18 to 25mm diameter = 0.5m/0.8m