Copper pipe cost/quality at screwfix

[gregmcateer]

Woody Alan,

I have used copper and plastic over the years, (JG Speedfit is my favourite plastic one).

If I understand you correctly, you are putting underfloor heating in solid downstairs - if so, I am not sure why you are using trays - that would be more likely if between joists. (Though I even used battens and screed between joists in one zone).

Regarding joints - I have just installed plastic pipe over 75mm of insulation board, then screeded with 75mm floor screed. It is over 50sqm, with 4-port manifold for the 4 zones. There are NO JOINTS under the floor - just four loops out and back to the manifold, as per the manufacturer's, (and all installers to whom I have spoken) advice.

I used kit from http://www.wundafloorheating.co.uk/ if that's any help.

Cheers

Greg

 

[Woody Alan]

Hi,

Well as the post is resurrected, I can say not only did I finish the project but I also moved house about 4 years ago. Going back over it, to answer some questions I finally got the pipe from B&Q and it bent ok in my bender. Maybe the wickes pipe was poorer quality just at that time I do know it was not such an orangey red more pink hue.
I used tray for future access or I would have been using vermiculite and rescreeding. I was very pleased with the end result although more work and cost the end result was a permanently flexible ring around the ground floor for future alterations, with no significant mess.
"I believe" rubber O rings WILL degrade at some point however far in the future. The other point and quite a significant one given the size of the tray is that plastic joints are enormous space wasters and woul;d not have fitted in the tray .
The only time I would consider using plastic is when access to fit copper is impossible due to joists etc and flexibilty is required.
All personal opinion of course.

Regards Alan

 

[Eric The Viking]

Since we're on the subject...

... I used to hire pipe benders years ago before buying my own. They don't need to be visibly worn to crinkle pipe. I got so frustrated once I took a length of copper into the hire shop and challenged them to find me a bender that didn't crinkle it. They couldn't. My "new" Record bender (now 25 years old) still doesn't crinkle pipe. I put this down to keeping it clean, taking care of the straight formers (easily damaged at the edges), occasional oiling of the rollers, and it being well made in the first place.

You can help the bend by removing any work-hardening in the copper tube before starting. This is handy for those tricky, complex shapes involving short bends in different directions. Run a blowlamp, ideally MAPP gas, over the tube length of the bend before starting, to get it pretty hot, then allow it to air cool (no need to quench - it's not steel). You can do this at the start of the job, and leave it to cool while you're getting on with the measurements.

Modern tube is definitely thinner-walled than the tube of 20+ years ago. I think it is more likely to crinkle, as there's less metal to stretch round the outside. I still use copper though, as the companies offering 50+ year guarantees on their plastic fittings won't be around then to make good any claims, and anyway, as I recently found out with a leaking stainless cylinder, suppliers have more get out clauses than a fishing net used for tadpoles.

The primary reasons for using plastic are lower capital cost, and faster installation (of smaller sizes). It's attractive to installers, but neither of these have any bearing on the value of plastic to a householder. Many plumbers, probably the majority, will say "I've fitted (insert big number here) houses with plastic and never had a problem", that's pretty much ALL they do - fit . They're not necessarily around five years later when the joints might fail.

The fact is that NOBODY knows what the longevity of plastic joints will be. Ageing is very hard to simulate, as are duty cycles. For example, joints usually have a pressure rating (often 3 bar, which is useless for practical porpoises in a tall house*), but there's no spec. for pressure cycling - pipes that have pressure changes. That's many pipes in a typical cold- or hot-water system.

I know of at least one housing association, which commissions a lot of new build in our area, that forbids ANY inaccessible plastic joints. They don't trust the systems that much. It's either a complete unbroken run, or it's in copper.

The one thing plastic pipes don't do, is corrode. With that single exception, I greatly prefer copper.

E.

(*32ft of water height = 1bar: what allowance for overpressure should you make? I think 100% isn't enough at these low pressures)

 

[RogerS]

......
The one thing plastic pipes don't do, is corrode.

E.
....

Or get nicked. Plastic works for me and I won't be around in 50 years time.

 

[Eric The Viking]

......
The one thing plastic pipes don't do, is corrode.

E.
....

Or get nicked. Plastic works for me and I won't be around in 50 years time.

Fair point. I know BT funded their switch to fibre optics years ago from the scrap value of the copper, so we may be forced to use plastic soon. That doesn't make it ideal though, IMHO.

E.

 

[RogerS]

One minor drawback of using plastic that I forgot to mention.

It only applies if you let the central heating water languish in some parts due to shutting of rads in some rooms etc. If your system has any tendency to creating hematite in it (and you don't have one of those Magnaclean devices fitted (and if you haven't got one fitted then get it fitted ASAP!)) then said hematite for some reason or other comes out of solution very easily in plastic pipes and sits there gradually blocking the pipe up. It seems to prefer doing this in plastic as copper pipe in the same circuit seems hardly to be affected.

 

[Graham Orm]

I use John Guest plastic all the time for bathroom and kitchen work, but 15mm only. If 22mm I use copper as I've found that the 22mm allows too much movement of the joint and they weep occasionally. If it was mine I'd use 22mm plastic with compression fittings. Copper is way too expensive now. However compression elbows will have a drastic effect on flow against radiused bends, depends how many you're fitting and the length of run. You could always use plastic and revert to copper for any long bends using compression fittings.

 

[Eric The Viking]

About two years ago, I happened to be around when a "plumber" used water to 'test-pressurise' the plastic under the floor of a friend's new bathroom (lots of t-joints and elbows). He'd been telling me how I was a dinosaur for not using it, how easy and fast it is, etc.

I'd been biting my tongue about the quality of the work (mate's rates, etc.), and had decided to stay well clear for fear of causing an upset. I genuinely just happened to be there at the time.

For 15 secs. or so of shouting, until the twit on the stop tap got the message, it did a passable impression of the Trevi fountains. It wrecked the ceiling decoration below.

All quite unnecessary. Any 'saving' from not using copper went in that 15 secs.

Great stuff - for decorators.

E.

 

[RogerS]

....
All quite unnecessary. Any 'saving' from not using copper went in that 15 secs.

Great stuff - for decorators.

E.

Nothing wrong with plastic water pipe whatsoever. Nothing is 'idiot' proof. If he didn't push the pipes in properly that was him....not the system.

Bloody daft pressurising with water anyway. You can get a very simple gizmo that you fit over an open end, and then pressurise via a side nozzle. Has a gauge on it....leave it overnight to see if the pressure drops.

As it would in lousy incorrectly soldered copper joints :wink:

 

[Eric The Viking]

Nothing wrong with plastic water pipe whatsoever.

With respect, Roger you can't know that. Neither can most of us. Specifically, there are lifespans quoted that are meaningless, and in any case significantly shorter than copper. Say it has a claimed "50-year lifespan": is that MTBF, in which case what does the curve look like, what failure modes are the early ones, how were those predictions obtained (test methodology, etc.)? People want to believe this sort of thing. The same questions need to be asked for all the jointing systems, too.

How do those numbers stack up against copper? What are its failure modes and MTBF, and why?

I've noticed a pattern: generally speaking, the older the building system, the better its longevity. Stone buildings with lime mortar and oak beams tend to do pretty well, although I appreciate that hollowed trunks as water pipes don't last all that long

Nothing is 'idiot' proof. If he didn't push the pipes in properly that was him....not the system.

I quite agree, except that he's apparently done this work lots of times. How can you not develop a 'feel' for properly-fitted joints? If you can't, some of the blame lies with the system, surely? Although I check well (and pressure test), I can tell if a soldered joint isn't right as it's being made, and usually correct it. It's a very long time since I've had one leak (compression fittings are another story though :-( ).

Bloody daft pressurising with water anyway. You can get a very simple gizmo that you fit over an open end, and then pressurise via a side nozzle. Has a gauge on it....leave it overnight to see if the pressure drops.

I agree here, too, which is why I mentioned the water specifically.

The trouble is that, never mind the real longevity (which I question anyway), plastic has a whole new set of problems and working practices. IMHO, it's _less_ suited to the DIY/handyman, because the mistakes are less apparent to a layman, for example inaccessible joints, earth bonding, and so on.

If I were fitting out farm buildings, I wouldn't hesitate to use plastic. But I won't have it in the house permanently.

E.

As it would in lousy incorrectly soldered copper joints :wink:[/quote]

 

[RogerS]

ETV...we were specifically talking about the joints and not the pipe in this context. I agree that there might be a question of longevity. But that is not the issue in this case. The only reason why a brand new system will leak is if it is not put together properly.....ie he hasn't pushed the pipe in sufficiently to engage. Doesn't matter how many times he has done it in the past. This time, he did it wrong. The leaks are down to him.....not the system.

For the record, our Hep2O central heating system is over 20 years old and no leaks.

 

[Gerry]

My house is nearly 50 years old now and still has the original plastic plumbing, Still quite flexible, not brittle and no leaks in the 24 years I have owned it.

Gerry

 

[Graham Orm]

Nothing wrong with plastic water pipe whatsoever.

With respect, Roger you can't know that. Neither can most of us. Specifically, there are lifespans quoted that are meaningless, and in any case significantly shorter than copper. Say it has a claimed "50-year lifespan": is that MTBF, in which case what does the curve look like, what failure modes are the early ones, how were those predictions obtained (test methodology, etc.)? People want to believe this sort of thing. The same questions need to be asked for all the jointing systems, too.

How do those numbers stack up against copper? What are its failure modes and MTBF, and why?

I've noticed a pattern: generally speaking, the older the building system, the better its longevity. Stone buildings with lime mortar and oak beams tend to do pretty well, although I appreciate that hollowed trunks as water pipes don't last all that long

Nothing is 'idiot' proof. If he didn't push the pipes in properly that was him....not the system.

I quite agree, except that he's apparently done this work lots of times. How can you not develop a 'feel' for properly-fitted joints? If you can't, some of the blame lies with the system, surely? Although I check well (and pressure test), I can tell if a soldered joint isn't right as it's being made, and usually correct it. It's a very long time since I've had one leak (compression fittings are another story though :-( ).

Bloody daft pressurising with water anyway. You can get a very simple gizmo that you fit over an open end, and then pressurise via a side nozzle. Has a gauge on it....leave it overnight to see if the pressure drops.

I agree here, too, which is why I mentioned the water specifically.

The trouble is that, never mind the real longevity (which I question anyway), plastic has a whole new set of problems and working practices. IMHO, it's _less_ suited to the DIY/handyman, because the mistakes are less apparent to a layman, for example inaccessible joints, earth bonding, and so on.

If I were fitting out farm buildings, I wouldn't hesitate to use plastic. But I won't have it in the house permanently.

E.

As it would in lousy incorrectly soldered copper joints :wink:

[/quote]

I use end feed copper fittings, compression fittings on copper and plastic, and most of all (daily), plastic pipe and fittings. Never pressure tested anything since I was at college. If I felt my work needed testing I'd pack up tomorrow. Honestly can't remember the last leak I had.

 

[Graham Orm]

My house is nearly 50 years old now and still has the original plastic plumbing, Still quite flexible, not brittle and no leaks in the 24 years I have owned it.

Gerry

Are we talking water or rainwater here? There was no plastic pipe that I know of 50 years ago, in fact they were still installing lead.

 

[Cowboy _Builder]

My house is nearly 50 years old now and still has the original plastic plumbing, Still quite flexible, not brittle and no leaks in the 24 years I have owned it.

Gerry

Are we talking water or rainwater here? There was no plastic pipe that I know of 50 years ago, in fact they were still installing lead.

When I started in the building trade in 1966 plastic pipes were being used as well as lead, my gaffer at the time said it would never catch on and wouldn't have anything to do with it ....well he got that right didn't he ... :roll:

 

[Graham Orm]

My house is nearly 50 years old now and still has the original plastic plumbing, Still quite flexible, not brittle and no leaks in the 24 years I have owned it.

Gerry

Are we talking water or rainwater here? There was no plastic pipe that I know of 50 years ago, in fact they were still installing lead.

When I started in the building trade in 1966 plastic pipes were being used as well as lead, my gaffer at the time said it would never catch on and wouldn't have anything to do with it ....well he got that right didn't he ... :roll:

You could have won a pint off me with that one! :shock:

 

[Eric The Viking]

The morning before my wife was due to come home from hospital with our youngest daughter, I went to wash my hands in the downstairs cloakroom of our newly-bought larger house, only to feel soapy warm water all over my feet.

The lead waste pipe, which I hadn't spotted when we'd looked round the place, had detached itself from the bottom of the basin.

Deep, er, joy.

E.

PS: I should add I had form: our eldest's triumphant arrival home to our previous property was similarly marred by the intense and 'interesting' smell of a dead mouse behind the architrave of our bedroom door. It had been carried into the house in the washing basket, probably from the long grass by the line. The family agreed that the ensuing fright when it jumped out, and the chase around the bedroom (until it reached the relative safety of an unfinished wall socket) had actually brought on labour.

I became 'aware' it hadn't survived a couple of days earlier, but couldn't find the corpse. When I finally did find it, with a torch and a mirror-on-a-stick, I still couldn't reach it without major demolition. I had to entomb it with expanding foam (the smell eventually went a couple of weeks later). New mum and new son came home to wrecked woodwork and a sheepish husband/dad. The mouse got its revenge, and I got the first entry in my 'criminal record'.

 

[Gerry]

My house is nearly 50 years old now and still has the original plastic plumbing, Still quite flexible, not brittle and no leaks in the 24 years I have owned it.

Gerry

Are we talking water or rainwater here? There was no plastic pipe that I know of 50 years ago, in fact they were still installing lead.

Water!
The only downside is it's not quite standard 15mm so a special (read expensive) compression fitting adapter is required to connect to 15mm pipe. All of the original joints in the pipe are glued.

The House was built in the late 50's so it's actually nearly 55 years old now!

Gerry