Most effective way of preventing Shower pipe from freezing

[ICanDoItWell]

I would like some advice on Insulating a 15mm copper pipe which is to be installed in my loft to feed a new shower.

Currently it uses 10mm copper pipe I believe but this is insufficient for the new 9Kw higher power electric shower.

I'm thinking about -19C temperatures and the effect on the pipe in the loft.

The water supply enters in the kitchen below the bathroom and goes through the walls to the toilet and then into a cupboard up the inside of what was a hot water tank space which now houses the condensing boiler. The pipe then goes up into the loft.

There is a shut off valve but I don't want to have to rely on it, draining the water from the shower is a problem.

My property is a mid terrace with no fines concrete walls, however it has recently been externally insulated with 60mm Kingspan insulation which is maintaining the internal temperature much better. Incidentally, the cold water pipes from the kitchen run close to the floor of the bathroom, run on mountings about 15-20mm from the outside wall (South-Westerly). Some of this is not externally insulated because there are tiles on the external wall with thermalite style blocks instead of no fines concrete. This will affect the temperature of the water in the pipe to the shower. The old shower did start to freeze up during that -19C winter which caused a leak and that is why I have had to replace it. The part costs over £60 and therefore it's not worth replacing for such an old shower which is totally inadequate anyway at 7.2Kw.

Therefore, what would be best to do?

I thought about maybe fitting the pipe as close to the plasterboard ceiling as possible and then insulating on top and hope for the best (pray it doesn't freeze). However I doubt that this would protect the pipe in the event of extreme cold.

I also thought about an electric thermostat powering a heating cable with a switch and temperature controller. Switch it on when the outside temperature is freezing and let it regulate the pipe temperature itself. Switching it off when it's not required during the summer etc. I need to employ and electrician to wire the shower so could have this done at the same time.

Recommendations and any links to products would be appreciated.

 

[PrenticeBoyofDerry]

As it's a cold water pipe your requirements is not only to prevent freezing but also undue warming of water, that can get back in to the drinking water and cause legionella.
Insulating the pipework is normally a good start, also heat tracing at a level of around 4 degrees C would be acceptable.

 

[ICanDoItWell]

As it's a cold water pipe your requirements is not only to prevent freezing but also undue warming of water, that can get back in to the drinking water and cause legionella.
Insulating the pipework is normally a good start, also heat tracing at a level of around 4 degrees C would be acceptable.

Thank you for pointing out the possibility of a problem if it's heated too much.

Therefore the idea I had about a thermal monitoring system of temperature sensor(s) and a heat element along the pipe should be the best idea. Having all that on a switch in the boiler cupboard with the temp monitor and temperature control. Then keep the temperature low as you suggest.

I will price the parts and see what the damage would be. If you know of any places that can supply them then a link would be appreciated.

For the pipe insulation, do you know of any type or make that would provide the most protection from freezing?

I would prefer to keep any electric heating to a minimum in order to not add to my already slightly above average electric usage. If the weather is really cold, it could be running for long periods.

 

[PrenticeBoyofDerry]

This will keep the pipe best protected
pipe insulation

 

[Madrab]

How about drilling the joist and therefore pass the pipe work under the loft insulation? That way the ambient house temperature will keep the pipe above 0 degrees, lag it too for double protection.

 

[ICanDoItWell]

The joists run perpendicular to the direction of the pipe which means it cannot be simply laid above the plasterboard.

The joists are also quite small in the loft at about 4", cheap build property that it is. If I cut into them the roof would collapse if any weight is up there, which there is.

A simple solution and fairly cheap to do but impractical in this property. Worth suggesting though so thank you.

The roof pitch is also quite low. The roof apex is only about 4' above the joists. It's quite cramped up there.

 

[PrenticeBoyofDerry]

You don't really want to run pipework within 350mm of the roof pitch, insulating the pipework and heat trace is going to be your best solution, if you cannot avoid having the pipe routed in areas that are susceptible to freezing.

 

[JohnD]

if the joists are only 4" then you can flop the second layer of insulation over the pipes. any exposed pipes should be lagged with Climaflex or similar in the "Water Regulations" grade which is as thick as your arm.

Flopping loft insulation over pipes has the advantage that they will be inside the warm envelope of the house.

 

[ICanDoItWell]

You don't really want to run pipework within 350mm of the roof pitch, insulating the pipework and heat trace is going to be your best solution, if you cannot avoid having the pipe routed in areas that are susceptible to freezing.

There is a large joist that runs the length of the house which is perpendicular to the other joists. That seems the best place to locate the pipework. I've measured from where the pipework would be to the roof felt and it's roughly 55cm. That is just above the main joists so it cannot go much lower if insulated.

if the joists are only 4" then you can flop the second layer of insulation over the pipes. any exposed pipes should be lagged with Climaflex or similar in the "Water Regulations" grade which is as thick as your arm.

Flopping loft insulation over pipes has the advantage that they will be inside the warm envelope of the house.

My house doesn't get that warm because I cannot afford to heat it very much and therefore I cannot really rely on heat from the house to keep it warm enough to prevent freezing. That is why I think that having a heating element in the pipe insulation might be the best idea. Have a temperature controller and sensor and have it all located and switched in the boiler cupboard which is fairly close to the pipework. The cold water pipe goes up from the boiler cupboard into the loft to feed the shower.

I will insulate it as well as possible and could easily throw some loft insulation over it. I have some rolls of insulation in the loft which I want to put down.

I just need to find a device to control the temperature, something which will fit in the boiler cupboard and do all that is necessary.