Warm drinking water

[leafy35lane]

Looking for some advice about drinking water to kitchen extension. We are having a water softener installed in our garage and this will be used everywhere other than to supply the kitchen sink for drinking water. A new pipe has been installed which bypasses the filter. All fine I think but I am concerned about the route that the plumber has used. Its probably around 15 metres from the garage and I am concerned about the water getting warmed. I thing water regs state that any warming above 20 degrees should be avoided due to legionella risk amongst other things.

About 8 meters is through ceiling right next to (within 30mm) the main flow from the boiler to a newly installed under floor heating system. To make it worse, the cold pipe is 30mm above the heating pipe - and heat rises of course. The plumber says he's going to lag the cold water pipe but I am concerned that the hot water will be flowing 24x7 and we won't be drawing cold water all the time. Won't the cold water sitting in the pipe inevitably heat up quite considerably over a few hours?

The last 3 metres to the position of the new sink (not yet installed) is under the screed floor next to the hot water pipe which is supplying the sink. The floor also has underfloor heating pipes installed but these are perhaps 400-500mm away from the cold water drinking feed. Again some wamring seems inevitable but I suppose when the cold water tap is run, the contents of the last 3 metres or so will run through quite quickly.

I am minded to insist that the pipe is rerouted so its not close to the flow/return for the underfloor heating AND its behind the cabinets above the warmed screed slab AND its lagged even though further away form anything warm/hot. Pipes (other than under the screed floor) are still accessible, no plasterboard on walls or ceiling (yet) so now is the time to deal with it rather than wait and test and find the water runs very warm when walls/ceilings are plastered and flooring down kitchen installed and be concerend for years about how much bacterial is building up in the pipe.

I think the response I will get is that lagging the cold water pipe will be adequate even though very close to other hot pipes and last few metres through screed not an issue. Will lagging in this scenario be enough or should I insist on rerouting? Would it be reasonable to take the stance that the route is unacceptable and it should have been installed away form other heat sources in the first place? Other routes are available with a bit of extra hassle - seems to me that following the underfloor heating pipe route was easiest so that was what was done.

Thanks in advance for any advice

 

[Madrab]

If the water is being used regularly then legionella shouldn't be an issue - that being said - you are correct that the water shouldn't be getting unusually warm - the key to that is insulation and avoid routing cold pipe with anything that is above ambient temp which seems to be what you are asking for.

If you want it done a certain way that isn't overly pedantic or outlandish, to ensure you are happy with it, then that is the way it should to be. It's not difficult.

 

[Deleted member 267285]

It’s being installed against the water supply (water fittings) regulations 1999 and lagging isn’t an acceptable way to circumvent the requirements. If you’re unhappy and your plumber insists then you could contact (or at least mention it as a precursor) the local water undertaker’s regulations department (these are who enforce the regulations).

 

[Stivino]

If I remember correctly, the water supplied to your home has to be between 5 and 25°C. If I am correct, it is possible (although highly unlikely) that it could be above 20°C in any case.

 

[Elsa TLC]

Regardless I'd insulate the hot and the cold for the entire route.

Cold to prevent condensation and
Hot to prevent heat loss.
Both to prevent heat transfer.

And depending on location it could prevent freezing and possible costly call outs

Elsa

 

[Elsa TLC]

Also be sure he hasn't used or will use compression of pushfit fittings under a screeded floor.

 

[leafy35lane]

Thanks everyone for the very useful feedback.

Yes Elsa, I forgot to mention that he has used several metal joints under the screed (plastic pipe). I’m no plumber but think they must be compression fittings. The fittings were wrapped in tape (just standard duck tape I think). Additional worry is therefore screed attacking the joints and joint failure / leaks. The joints will be under expensive engineered wood flooring and the kitchen units in a month or so. Think regs say pipes must be ducted when concealed and any joints accessible through some kind of door/box. Neither has been done. The pipes enter from the ceiling then pass down a route chiselled into block work down a side walll before entering the screed Seems sensible precaution to divert the pipes above floor level (hot, cold and hard drinking feed) as surface mounted pipes (after plaster board installed and plastered) close to the wall to sink and dishwasher position. Pretty sure the kitchen cabinets have a small rear allowance for pipes so pipes won’t be visible. This way any joints will be more accessible through back of cabinets in the event of failure rather than under the screed. Pipes can be lagged and won’t be warmed by underfloor heating

Sound sensible —even now obvious - to me as a none plumber and not a big job. What do others think?

Based on feedback, I’m now likely to ask for a different route through the ceiling away from the underfloor heating flow and returns. And fully lagged drinking water and any hot water pipes that are close and can’t be avoided……And a debate on extra time/cost I’m sure.

Biggest cost concern will be postponing other things -plasterboarding booked for tomorrow- but I’m now feeling justified and strongly that corners are being cut.

 

[flameport]

he has used several metal joints under the screed (plastic pipe).

Shouldn't be any joints of any kind under there - pipe needs to be in one continuous length.

 

[Elsa TLC]

Thanks everyone for the very useful feedback.

Yes Elsa, I forgot to mention that he has used several metal joints under the screed (plastic pipe). I’m no plumber but think they must be compression fittings. The fittings were wrapped in tape (just standard duck tape I think). Additional worry is therefore screed attacking the joints and joint failure / leaks. The joints will be under expensive engineered wood flooring and the kitchen units in a month or so. Think regs say pipes must be ducted when concealed and any joints accessible through some kind of door/box. Neither has been done. The pipes enter from the ceiling then pass down a route chiselled into block work down a side walll before entering the screed Seems sensible precaution to divert the pipes above floor level (hot, cold and hard drinking feed) as surface mounted pipes (after plaster board installed and plastered) close to the wall to sink and dishwasher position. Pretty sure the kitchen cabinets have a small rear allowance for pipes so pipes won’t be visible. This way any joints will be more accessible through back of cabinets in the event of failure rather than under the screed. Pipes can be lagged and won’t be warmed by underfloor heating

Sound sensible —even now obvious - to me as a none plumber and not a big job. What do others think?

Based on feedback, I’m now likely to ask for a different route through the ceiling away from the underfloor heating flow and returns. And fully lagged drinking water and any hot water pipes that are close and can’t be avoided……And a debate on extra time/cost I’m sure.

Biggest cost concern will be postponing other things -plasterboarding booked for tomorrow- but I’m now feeling justified and strongly that corners are being cut.

I'd have serious concerns with this plumber.

I prefer press fit and copper, but accept push fit is the future and for the time being.

Fitted correctly it works well.
Fittings; I use at a minimum and always where they can be maintained. Compression fittings more so. Never under expensive floors.

Be sure to take photos do not pay cash and tell the builder and the plumber of your concerns.

To my belief any insurance company would be chasing the plumber for any future claims. But that's only upto 6 or 8 years I believe.

 

[leafy35lane]

Following all the advice, I've tackled the issue with the builder today and asked that the cold water feed follows a new route through ceiling well away from heating pipes and that the section under the screed is disconnected and rerouted in a channel in blockwork round kitchen wall behind cabinets. All resolved seemingly amicably and the builder is now taking it up with and instructing the plumber (his subcontractor). Other works postponed until this is done. No mention of costs but we'll see - based on everyone's advice, I think the plumber is really just doing what should have been done from the start. It now seems to me that its not a huge amount of work (though the only obvious alternate route is a bit awkward) but compared with what would be required later when the floors down, walls plastered and kitchen in, doing it now is easy.

Very grateful for all the advice.

 

[Deleted member 267285]

Following all the advice, I've tackled the issue with the builder today and asked that the cold water feed follows a new route through ceiling well away from heating pipes and that the section under the screed is disconnected and rerouted in a channel in blockwork round kitchen wall behind cabinets. All resolved seemingly amicably and the builder is now taking it up with and instructing the plumber (his subcontractor). Other works postponed until this is done. No mention of costs but we'll see - based on everyone's advice, I think the plumber is really just doing what should have been done from the start. It now seems to me that its not a huge amount of work (though the only obvious alternate route is a bit awkward) but compared with what would be required later when the floors down, walls plastered and kitchen in, doing it now is easy.

Very grateful for all the advice.

I would be arguing the toss for costs - you didn’t know that it shouldn’t be installed this way, and if water regs inspected it afterwards they could force the plumber to change it at their cost!