hot water pipe run

[Fred]

Hi,

The water pipes in my kitchen are copper pipes buried in the concrete floor without any insulation. I am hoping to redecorate the kitchen and was hoping to re-route the pipes so that I could insulate them. Presently it takes some time to get hot water at the hot tap.

To complicate matters I have a door on either side, so I can not run pipes horizontally along the walls without hitting a door.

What is the group's opinion on the best way to run the pipes?

I could dig up the floor and bury new pipes in lagging but that sounds like a messy job.

Another option is to box them in at ceiling level above the door. After the door I could continue at ceiling level or drop them out-of-sight, behind the kitchen units. I think boxing could look ugly but perhaps in bathrooms and kitchens you can get away with it?

My other idea is to pass the pipes through the joists in the ceiling above. On the plus side, the pipes would be out of sight, except for one drop in the corner. But I fear there are disadvantages. The boiler is in the middle of the kitchen and the bathroom is above. So there are already a lot of pipes going through some sections of the ceiling and the ring main also passes through those joists, so there is not a great deal of room left. I could run the hot water pipe through but I think I would have to leave the cold water pipe in the floor.

If I did go through joists, I would have to use plastic pipe. Some people claim copper is better as it is antibacterial, so I wonder if copper would be better for hot water?

TIA for your opinions

[Toby]

If the pipes are directly buried in the concrete without any protection from the concrete, you really need to replace these anyway, as the concrete eats the copper, so you will need to do both hot and cold if this is the case.

Is your hot water supplied by a combi boiler (so heated on demadn) or from a hot water cylinder? What size are the pipes in the floor - if they are 22mm, then they will take a lot longer to purge than 15mm.

Without actually seeing where everything is, it is hard to say what is best - how about some photos of the kitchen to help visualise it? (You can upload them to somewhere like tinypic.com then post links to them)

I wouldn't worry about plastic pipes and antibactierial, the pipes they are installing in the road, and between the road and houses are all plastic nowadays.

[Fred]

Yes, I had heard that. I have "excavated" the CH pipes in some of the other rooms because I was hoping to reduce my fuel bills by lagging the pipes. I used plastic pipe which I lagged and then wrapped it all in strong plastic and concreted back over them. I'm thinking now that it might have been better to bring them above the floor.

I don't think boxing looks pretty. I have seen exposed pipes painted the same colour as the skirting board. Some people like this, some do not. I guess it is a matter of personal taste. If I did it again, I wonder whether I might use chrome plated pipe. True, it would not be lagged but would that matter if the heat was escaping into the room?

Cylinder.

I believe they are 15mm.

[Fred]

The cylinder is central to the house but the sink is under the kitchen window so at one end of the house. I know some people use an electric heater but then I'd have the problem of having to route 6mm^2 (?) T&E to the sink and get a bigger fuse box to accommodate another MCB!

Why are pumps so expensive to run. I thought they were only about 40W, though I appreciate if they were on all day, it would add up.

[John Williamson]

The cost of running a pumped domestic hot water system with continuously circulating hot water isn't so much the energy used by the pump, but the energy lost from the pipes the hot water is constantly circulating through. This can add up to a few hundred watts just to keep the hot water hot as it circulates. It's worth it for a hotel, but not for a house (in general).

[Tim Lamb]

In message , Fred writes

Look up earlier threads on *under sink water heaters*. The pressurised storage types do not have a huge electrical load and are perfectly adequate for normal kitchen activities.

[Fred]

What were water mains before plastic came along? Iron? I guess copper was never used because of cost. I wonder whether it is less important with cold water, whereas warmer water might encourage bugs to breed? Hopefully the pipes in the road have constant flow so bugs never hang around long?

[Fred]

Thank you. I hadn't understood that before.

[Fred]

Thanks.

[Toby]

Buried and protected from the concrete is fine and looks better, but does take considerably more effort to do! The fact they are now insulated will mean a lot less heat is lost to the ground.

For CH pipes, no, as they are used in the winter and just act as more radiation of heat into the room, you should lag them if they are passing through somewhere you don't want heated (or needs protection from frost, like under the ground floor)

For hot water, in winter, no, in summer, heat is wasted, but not enough to worry about in a domestic environment where hot water is not used all day IMHO. If pipes are buried directly in concrete, the concrete will suck the heat out of them far more then them being in free air, or lagged in concrete.

Do you get adequate flow from the hot water in the Kitchen, if the flow is really slow, then it will take even longer to purge, you could install a shower type pump on the hot side (I am assuming the cold is direct mains pressure in the Kitchen, not from a tank)

[Jeremy Nicoll - news posts]

Lead, at least in the house and out to the street. ("Plumbers" are called that because the latin word for lead is "Plumba"; the Romans had lead water pipes & troughs.)

Water sitting in lead pipes caused lead poisoning, which is one reason why people used to let a tap run for a while before filling a glass.

For years one could get grants to subsidise or totally pay for the cost of replacing lead supply pipes by plastic.

[Fred]

I don't think the flow is particularly slow but I haven't measured it. Your idea about a pump is a good one. Other posts have said circulating the water is expensive but with this arrangement, the pump would only move water when the tap was open, so might give the best of both worlds (and yes, the cold water is mains).

Thanks again.

[Steve Firth]

That's not really the water main.

Water mains tended to be cast iron, in relatively recent history. Before that they could be elm.

Errm. The Latin term for lead is plumbum nigrum.

No, it didn't by and large. In hard water areas it really didn't and in soft water areas people may have got a bit more lead in their drinking water than was good for them but it still didn't really amount to poisoning. Arguably they were ingesting more lead from petrol.

[charles]

unlikely if they were Romans. OTH, I grew up with soft water and lead pipes and I don't think I got poisoned.

[The Natural Philosopher]

IIRC its plumbum

[Doctor Drivel]

Nonsense. Well insulated hot water pipes keep the heat for quite a wile.

[Doctor Drivel]

But it affected brain cells, hence why the people of Glasgow were violent. The very soft water dissolved lead.

[polygonum]

Water sitting in a pipe is unlikely to cause any form of bodily damage and probably a 100% certainty it won't poison. It is when it stops sitting in a pipe that a problem might occur. :-)

Way back in a physics lesson (I think) we worked out that the amount of water that people were 'supposed' to draw before collecting for use was not optimum. It was fairly close to the amount required to ensure the water with the highest concentration of lead would be what was used. Obviously this depends on the pipework, etc. but I think it was based on a fairly typical local house. And no, I cannot remember how much should be drawn.

[Steve Firth]

[snip]

Difficult to tell if the OP was confining his comment to Romans. Lead was used right up to and after the 60s.

If we are on about Romans and lead poisoning then their use of lead compounds to sweeten food must get an honourable mention.

[ARW]

So that is why they married their horses.