22mm pvc pipe instead of copper?

[Henrik]

Long story, but I need to run a 22mm pipe from the hot water tank upstairs to the kitchen tap, which is about 10m pipe run away, but through floor joists, through a double skin wall etc etc.

Recently when my parents in Sweden had their water pipes replaced, the plumbers replaced them with PVC (I assume - some clear plastic) tubing which has no joins apart from where it joins to the heating system and the tap.

Theirs seems to be about 15mm diameter and it runs on mains pressure, so the flow is really good, however here in England, of course we're often stuck with the old water tank in the loft type pressure, which is why I'd want to stick with 22mm as far as possible.

Anyway, I notice that e.g. screwfix sell the plastic pipe now, and I quite like the of no joins in the walls etc, but thought I'd check here first to see if anyone's used it successfully?

The run will be awkward with copper piping (lots of 90 degree bends to get it to its final position, hence thinking of using plastic instead if possible.

I'm not too worried about cost of fittings etc, but mainly about getting reasonable flow.

 

[Lufbramatt]

For drinking water it probably wont be PVC pipe, it will be MDPE or some sort of barrier pipe like JG speedfit or Geberit Mepla. They have a metal layer (aluminium or copper usually) to protect against contamination. The biggest issue is controlling expansion and contraction from temperature changes, the pipe can pull joints apart if not installed correctly.

I used to be a product manager for Geberit UK looking after piping systems (Mapress and Mepla) when they were based in Aylesford near Maidstone. Used to get all the competitors stuff in to look at and take to bits. All the plumbing I've done in my house is with soldered copper..

 

[Wendelspanswick]

I switched to plastic pipe about 10 years ago, using either JG Guest stuff from Screwfix or the Toolstation equivalent. Fitted about 200m of the stuff in various new extensions/refurbs and haven't had any failures leaks or issues.
There is a new housing estate going up on the other side of town and it's all plastic pipe that's going in.
For your install I would use 22m copper on the 500mm from the tank but the rest I would do in plastic.

 

[angellonewolf]

sorry im old school my votes for the copper as i have said on another post mate works for british gas first thing thay look for when theres a leak is plastic pipe then compression joints then the copper pipe all ways in that order it rare he said to ever get to the copper search

 

[Lufbramatt]

Its good stuff if it's installed properly, the trouble is you can assemble it so that it appears to be sealed but over time the joints work loose if the pipe isn't inserted all the way into the fitting and you get movement on the pipe due to expansion and contraction (its something like 10x more than copper).

I was on site at a new build school in south east London once where they had to dig up about 200m of corridor where plastic pipes had been incorrectly joined, passed the pressure test then started leaking 2 months later when the kids had started school.

 

[Seadog]

If you're going through joists then you have no option but to use plastic, unless you want to start notching, which is not ideal. Make sure that fix sleeves in the pipe, stainless ones are best IMO. When pushing into a fitting use some lube, spit is fine or mildly soapy water and make sure it snaps home. A lot of problems are down to people thinking that the initial push is all that's required, it's not, keep shoving it in () until it slides in and comes to a positive stop. Do a trial fit on the bench first if you're unsure of the feel.

 

[Cobbler]

I have just chased a leak in my sons central heating. Found it under a T&G chipboard false floor. A mouse had eaten through the plastic pipe. 2 hours to cut up the chipboard with a circular saw, 2 minutes to repair the leak! I would be wary of using plastic somewhere that mice could get at & also somewhere that you could not get at in the case of a leak.

 

[Henrik]

Thanks guys, I'll give the plastic pipe a go. I can get reasonably easy access to most of it, and I will be able to get to all the joints.

 

[carbon]

I fitted some of the guest piping about about ten years ago. I've have no leaks but there pipe was marked to make sure pipe and fittings were installed correctly. I think it was cut the pipe at one mark then install the support sleeve in the pipe then push the pipe into the fitting until the next mark was just covered and that was it

 

[brightspark]

quite frankly I only fit copper pipe but if its only on a hot water supply and no joins apart from each end I would run it through if it made the job a lot easier. if it did leak at the joints it would be easy to spot and accessible

 

[Kayos]

On a hot pipe it doesn't even need to be barrier, if you have to feed it through allsorts it might get a bit stiff

How old is the existing?

 

[123hotchef]

I used the 22mm under the whole of my down stairs heating system like you say no joins it can be a bit memory happy but if u rub and bend it in the opposite direction it will be fine as said cut it square and use inserts push it home fully into the fitting also. get urself a ratchet style cutter for it

 

[DrDeAtH]

Another vote for doing it properly in copper tube. Use pulled bends where possible, instead of soldering in loads of elbows.
It's rodent proof too.

 

[Wendelspanswick]

One advantage of plastic over copper is you can thread it through difficult to access areas without having to lift the floorboards.

 

[Kayos]

I remember years ago talking to an old time plumber about plastic

He said "when copper started being used we all thought it was too light and thin, never be as good as the old lead..."

 

[gaz1]

I remember years ago talking to an old time plumber about plastic

He said "when copper started being used we all thought it was too light and thin, never be as good as the old lead..."

isnt that the same with the plastic pipe being used nowadays as i must admit id rather plumb in with copper myself

 

[Kayos]

I use copper 99% of the time (I am a heating engineer) but the 1% the plastic is used its needed and the best option

 

[brightspark]

all modern plumbers swear by plastic. yea cos there a lazy pack of sods and its easy to fit and more profitable

 

[Tigman]

Im the same only use it when its convenient, ie ( getting through difficult places ) always use copper when its on show !

 

[123hotchef]

copper to plastic can be a point for failure too I found a leak in a place I look after the o rings in the push fittings had perrished on the copper pipe and water was peeing out