Supporting pipes under floorboards + insulation

[kasser]

Hi,
How do I support with clips pipes run under a floating timber ground floor? The joists are too small to notch or drill into and in any case, there's plenty of space underneath. Where do you place the pipe clips if running perpendicular to the joists?
And if plastic pipes, this means lots of clips, every 300 mm for Speedfit! Lots of floorboards going up?
I've never had to do this yet.
Now I've got a job fitting central heating in a bungalow. Pipes could go under the wooden ground floor or over in the loft. Which route would you take? What insulation would you use? Finally, how do you fit the insulation snugly around with plastic pipe clips in the way?

 

[kasser]

4 bedrooms, 2 living rooms, conservatory, office, en-suite, etc. I was surprised at the number of rads too.

 

[Jerry]

No way I am lying on my back soldering pipes above my head. Plastic all the way.

If i am running perpendicular to the joist i will drill. I make up a drilling template from cardboard (for depth of wood and space between pipes) and a laser level to keep everyhting straight.

If i cannot drill when running perpendicular, then i will use Talon pipe clips with spacers and a laser again. I find an impact driver is small and quick in tight spaces. I also make up all the pipe clips before starting.

If i am running parallel, then i use Talan pipe clips on the inside of the joists or if their is not enough room, then a cheeky batternscrewed to the underside of the joists.

People are moaning about the spacing for plastic pipes. I generally add way more, especially at bends. Plastic pipe can be arguementative and needs to be wrestled into place frequesntly and the additional clips help.

As for insulation, i generally go with cheap 9mm wall. Each section is cut in between clips. If its in an area where there could be high heat loss, then i cover the expsoed clips with more insulation. Insualtion on show gets the treatment from my new pipe lagger pro cutter thingy.

 

[kasser]

People are moaning about the spacing for plastic pipes. I generally add way more, especially at bends.

Try adding way more when screwing the clips under the joists! Not easy.

You could use straight 3m of plastic pipes. Easier to work with and not much more expensive, though if you need long runs, you'll need to join them which defeats a little the advantage of using plastic.

Shouldn't your pipes in the pic be spaced further apart? 3 times hole diameter?

 

[ShaunCorbs]

Try adding way more when screwing the clips under the joists! Not easy.

You could use straight 3m of plastic pipes. Easier to work with and not much more expensive, though if you need long runs, you'll need to join them which defeats a little the advantage of using plastic.

Shouldn't your pipes in the pic be spaced further apart? 3 times hole diameter?

Correct

 

[Jerry]

I knew you guys would see that! Well spotted!

Yep, the pipes were not in my first choice location. The client refused to let me space them out. I have no idea why.

Truthfully, I can find it very hard to meet the drilling and notching regs. Especially when you are coming across old joists that have been ravaged by previous trades.

 

[ShaunCorbs]

I knew you guys would see that! Well spotted!

Yep, the pipes were not in my first choice location. The client refused to let me space them out. I have no idea why.

Truthfully, I can find it very hard to meet the drilling and notching regs. Especially when you are coming across old joists that have been ravaged by previous trades.

Especially sparkles

 

[Jerry]

Especially sparkles

Are they like twinkles? but with more glitter and unicorns?

 

[ShaunCorbs]

Are they like twinkles? but with more glitter and unicorns?

sparkies

 

[gmartine]

I've used stainless cable ties and mounts for securing heavily insulated pipe in awkward places before ... rock solid and insulate to your heart's content. A bit overkill and made for cable but it's the business.

 

[Aire]

I knew you guys would see that! Well spotted!

Yep, the pipes were not in my first choice location. The client refused to let me space them out. I have no idea why.

Truthfully, I can find it very hard to meet the drilling and notching regs. Especially when you are coming across old joists that have been ravaged by previous trades.

I wasn't aware you could go against building regs because the customer says so. I'll remember that next time I'm asked to flue the boiler out the window because they don't want a new hole drilling

 

[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