Hot water ring main in the bungalow roof void rather than screed

[bngimages]

We are considering having our house rads and hot water system replumbed so it's not buried in the 1970's screed that it is at the moment. The cement progressively eats away at the copper if it is not wrapped in Denzo tape (no way to tell without digging up the screed).

We are thinking of replacing our ageing oil boiler with a heat pump which means we will be on mains pressure -significantly more than the gravity feed tank we have at the moment - which will make a leak even more likely.

Apparently some people in bungalows have a put in a piping ring-main in the roof void with vertical drop-downs in each room to the rads, or wherever hot water is needed. I imagine that 2 storey houses have a water plumbing system around the first floor, so having piping out of the screed and above the first floor is perhaps not unusual.

Is this piping ring-main in roof void a bad idea, if so why? And what piping would be good to use? Is multi-layer piping (plastic and aluminium) the stuff to use?

Any help much appreciated!

 

[king of pipes]

Upgrading your system is probably one of the most expensive projects you can do to your home , we are all different in the way we work, my advice is employ a reputable heating company to vist you for a survey , if your determined to go down the renewables route then insulation of your home the walls , ceiling voids and windows is a must, personally i would renew everything if the budget allows . Regards kop

 

[SimonG]

Done a couple, all in copper. Boiler wouldn't hold pressure. Not worth finding and repairing as the rest of the pipe in the screed will be in just a bad of condition.

 

[Ben-gee]

There is a road of about 100 houses near me built in the eighties with all poor quality copper pipes directly in the screed.

Not a single one of them is on the original pipework anymore...,.

 

[bngimages]

Thank you. That's helpful.

We have insulated cavity walls, double glazing and I'm in the process of upgrading the roof void insulation to 300 from 100mm to satisfy the EPC recommendations.

The heating company that surveyed said they could put in a hot water and rad system ring main in the loft, but were proposing plastic pipes, I imagine with push fit connections. It didn't sound too well thought out, but I'm no expert.

Would plastic pipes with push-fit be OK? What about air-locks - should there be a slope on the piping somewhere? Are mice gnawing the plastic piping a potential problem? What are the advantages / disadvantages of copper? Would multi-layer piping be a good idea?

Any thoughts helpful

 

[SimonG]

I take it you are out in the sticks, so copper for me and installed prior to the new roof insulation.

 

[king of pipes]

Have to agree with Simon if your in the country then it's best to use copper and It must be pressure tested and well insulated before any rolls of insulation are added to the loft void . Kop

 

[ShaunCorbs]

Only disadvantage of copper is time it takes to install over plastic and make sure they do 15mm to each rad and not 10mm

 

[Scott_D]

Is there room to crawl around up there? safe to do hot works?

 

[king of pipes]

Crimp fittings and copper are a option and avoids any contamination of the system and any risk of fire during installation . Kop

 

[bngimages]

Thanks muchly again! There is plenty of room and easy access to the roof void as there's stairs and a small room in the middle of the loft, so easy access all around it.

'Scuse ignorance but why does being in the country (we are in a small village) mean copper is best?

How about this stuff? Multilayer piping:

- The benefits of flexible multi-layer piping - https://www.phamnews.co.uk/the-benefits-of-flexible-multi-layer-piping/
- Heatwave Multilayer Pipe and Fittings | Renewable Heating | Thermal Earth | Thermal Earth - https://www.thermalearth.co.uk/Category/multilayer_pipe_and_fittings/42

Seems like it combines the best of both worlds. Has anyone used it?

 

[Ric2013]

We are considering having our house rads and hot water system replumbed so it's not buried in the 1970's screed that it is at the moment. The cement progressively eats away at the copper if it is not wrapped in Denzo tape (no way to tell without digging up the screed).

We are thinking of replacing our ageing oil boiler with a heat pump which means we will be on mains pressure -significantly more than the gravity feed tank we have at the moment - which will make a leak even more likely.

Apparently some people in bungalows have a put in a piping ring-main in the roof void with vertical drop-downs in each room to the rads, or wherever hot water is needed. I imagine that 2 storey houses have a water plumbing system around the first floor, so having piping out of the screed and above the first floor is perhaps not unusual.

Is this piping ring-main in roof void a bad idea, if so why? And what piping would be good to use? Is multi-layer piping (plastic and aluminium) the stuff to use?

Any help much appreciated!

Multi-layer Composite Pipe works well, but if I were to come across 16mm MLCP in the course of works, it simply isn't common enough for me to carry the appropriate fittings. I'm yet to be convinced it's any better than 15mm polybutylene (eg Hep20 and Speedfit), however, which is much more a standard item.

Copper is good, and something I and most plumbers would always have the parts for in the van. It is also what I would favour in my own house.

I am not against polybutylene, but it does have a tendency to be thrown in, because you can get away with doing this - most of the time. But I suspect this will be at the cost of durability. Installed correctly, I'm not convinced polybutylene is much quicker or cheaper and I have my reservations regarding the longevity of the push-fit joints. It does have the slight advantage of being non-metallic, which (unless the electrical regulations have changed) means no earth bonding of the radiator would be required in the bathroom and marginally less risk of system corrosion.

 

[ShaunCorbs]

I use mlcp all the time for my new work eg new / new systems it’s better than plastic but the install speed is the same and you can have secondary returns in them as plastic you cant and it’s guaranteed once installed

but most plumbers don’t Carry the kit for it / know what it is

 

[king of pipes]

In the country you are prone to rodent infestation mice and rats love to cheew on plastic pipework it may come as a shock but this can and does happen as theres plenty of room i would use copper and crimp fittings for the install . Kop

 

[Ric2013]

Why are we suddenly against conventional soldered joints? I know it's loft work and there is a fire risk during installation which requires extra care and attention, but I've never not soldered. Has protocol suddenly changed in the last 9 months since I've been abroad?

 

[king of pipes]

Why are we suddenly against conventional soldered joints? I know it's loft work and there is a fire risk during installation which requires extra care and attention, but I've never not soldered. Has protocol suddenly changed in the last 9 months since I've been abroad?

we are not against them bud and to answer your question no protocol has not changed soldered joints are perfectly acceptable, but for renewables heat pumps , plant and equipment its quite normal to use copper tube with press fit fittings even stainless or carbon steel press fit on larger installs up to 108 mm in diameter it avoids the use of heat in the roof space its quicker with sections of supply pipework being fabricated before being crimped up it also avoids contamination of the supply pipework and equipment from flux and solder all thats needed is a cold and hot flush avoiding any chemicals being needed to clean the system internally , self cleaning acid type fluxes are corrosive if left in a newly installed systems often resulting in green residue being present it is essential this is removed as if left in it can cause pin holeing and leaks down the line . Regards kop

 

[Ric2013]

all thats needed is a cold and hot flush avoiding any chemicals being needed to clean the system internally

If the OP has new rads though, wouldn't you need some X300 to get any residual oil from fabrication remaining in the radiators, particularly if there are any EPDM rubber seals in the system that will be very vulnerable to oil, or do you think that is largely a myth perpetuated by the inhibitor manufacturers?

 

[bngimages]

Just to say thank you everyone for your thoughts. Most helpful.

 

[king of pipes]

If the OP has new rads though, wouldn't you need some X300 to get any residual oil from fabrication remaining in the radiators, particularly if there are any EPDM rubber seals in the system that will be very vulnerable to oil, or do you think that is largely a myth perpetuated by the inhibitor manufacturers?

Manufacturers instructions i guess bud . Kop