Brand new central heating/water system. Plastic or copper?

[MrS]

Its obviously easier to do a new install for a combi boiler in plastic but ive never used it before.

What is a rough price difference for using plastic? is it much more expensive over copper?

Is it easy to do? is there different types of plastic, different thicknesses, different fitting etc etc? do you run it just like copper where you use 22mm and 15mm pipes?

Thanks

 

[HarrogateGas]

I always use copper, Yes it takes a bit more time to install but once its in its withstands time and use more. It survives the knocks from the hoover etc.


I really cant see plastic fittings being leak free in 30years but a copper soldered joint will last a life time.

 

[Softus]

I always use copper

I use both, because they're suitable for different scenarios.

Yes it takes a bit more time to install but once its in its withstands time and use more.

My assessment is the reverse. And copper tubing doesn't last forever.

It survives the knocks from the hoover etc.

My assessment is the reverse. And, should a plastic fitting leak, you can dismantle and assemble it many times more quickly than copper.

I really cant see plastic fittings being leak free in 30years but a copper soldered joint will last a life time.

This sounds like a blind prejudice.

What is a rough price difference for using plastic? is it much more expensive over copper?

For a given job, the cost in parts and labour often ends up being the same, because plastic is so much quicker.

Is it easy to do?

Yes, but you have to take care of your tubing, not scratch it etc., because of the 'O' ring seal.

is there different types of plastic, different thicknesses, different fitting etc etc?

There are different brands, and there is standard and barrier pipe. The wall thickness might well vary between the different brands, but who cares?

do you run it just like copper where you use 22mm and 15mm pipes?

Clearly not, because it bends and because you can get long coils of it, so on first fix jobs you would use far fewer fittings.

 

[chrishutt]

is there different types of plastic, different thicknesses, different fitting etc

Two types of plastic - Pex (polyethylene) and PB (polybutylene). All have the same external diameter (for a given nominal size - e.g. 15mm) but PB (I think) has slightly thicker walls and so the inserts are a different size. The inserts must be used and be appropriate for the type of pipe.

Two types of fittings - push fit and compression. There are lots of different makes of push fit (Hep2O, Speedfit, Polyplumb, etc.) but they all fit any tube (including copper). Brass compression joints are much cheaper but take longer to fit and need better access to tighten nuts.

However compression fittings can compensate for minor scratches on the tube which might cause a push fit fitting to leak, and they may prove more durable then push fit. Compression fittings used on plastic require quite a lot of tightening - make sure you're using the right inserts for the tube.

You can mix and match copper and plastic tube, and push fit and compression fittings. The first metre or so from the boiler should be copper anyway and exposed pipework generally looks better in copper. On the other hand plastic can be cabled under floors and through joists and voids in a way that is so much quicker and simpler than copper.

 

[JPC]

a fellow plumber told me the americans are taking out their speedfit as it leaks.
he told me they have had it some 10 yrs longer than us and now find the seals are perishing....particularly on the c/h (heat)

i cant find anything on the net to back it up but might be worth a bit more searching (only spent 10 mins searching)

 

[ollski]

a fellow plumber told me the americans are taking out their speedfit as it leaks.
he told me they have had it some 10 yrs longer than us and now find the seals are perishing....particularly on the c/h (heat)

i cant find anything on the net to back it up but might be worth a bit more searching (only spent 10 mins searching)

I do anything I can to stay away from plastic, several times I have been to fittings which are out of the way and have just decided to start leaking....2 in my own house from the days I thought plastic was a godsend!. Cheap looking, nasty,unproven, overpriced imho anyway.

 

[Softus]

I do anything I can to stay away from plastic, several times I have been to fittings which are out of the way and have just decided to start leaking....

...compared to how many times that poorly installed compression fittings leak, and copper tubing corrodes?

Cheap looking

What - compared to Endex - the most horrible looking joint in the known universe?

nasty

What - like Nasty Nick?

unproven

What - even after 30 years?

overpriced imho anyway.

How so? The job ends up being the same price to the customer, because there's less labour. Which means that more customers can be satisfied than when using only copper.

 

[Soggy_weetabix]

For and against on this one.

Being a gas engineer rules out plastic for most of my pipework.

Personally I would say commen sense prevails. No underfloor push fits that are innaccesible.

No innacessible compression fittings either.

In fact....run the whole system in one bit of bendy, proven not to leak in one thousand years special fix aluminium / titanium / plastic / copper pipe.

Might not be cheap. Lot less leaks than Wales though boyo.

David

 

[ollski]

Very difficult to reply when you split the posts mate but I will try to clarify my personal opinions.
I don't really think it's fair to compare a properly fitted pushfit joints which one day decides to spring itself of its own accord to a poorly fitted solder or compression joint. Copper tube doesn't corrode if adequately protected, not in my lifetime anyway.

It just looks cheap and nasty to me and screams DIY, normally forced round bends etc....be fair there aren't many plastic pipe jobs you walk into and think "wow that looks nice and professional", there may be some, but I have never seen any.

Sorry but I stick with unproven, I have never seen 30 year old plastic pipe installations and the older stuff I have seen has all been un barriered and trashed the system which isn't a particulaly impressive track record.

Yes cheaper to install but as a fitting still overpriced. I have used it alot, but sorry in my opinion it is not a realistic substitute for copper.

 

[chrishutt]

I think we should distinguish between plastic pipe and push-fit fittings. They do not necessarily go together - they can be used with brass compression fittings or copper tube respectively.

I personally have more confidence in plastic pipe than I do in push-fit fittings. I'm happy to use the pipe wherever it is significantly quicker to install, but I tend to use it with compression fittings. Push-fit fittings, although still relatively expensive, have their advantages, but I'm reluctant to use them in inaccessible locations like under floors.

 

[offroader]

When BG fitted our CH, they wouldnt use plastic, other companys quoted did use plastic, own personal preference maybe?

However BG did comment that the reason they didnt use plastic was because the fact that the hot cold hot cold process isnt going to do the plastic much good, and they didnt want the hastle of leaks in time.

And slighty off topic, but last month I had a callout to a house to check water damage on an alarm panel where a plastic pushfit fitting broke under their bath on NYE flooding the whole house whilst they were away.

 

[CorgiIOW]

Personally, i dont use plastic pipe, but what i have heard is that certain inhibitors, over a certain time, rot the rubber 'o' rings in speed fit fittings, thus a leak !

Although, i stand to be corrected.

 

[Agile]

Even though plastic CH makes up about one in 20 installations in London almost half of the leaks I am called to sort out are on plastic systems.

Either they have just decided to leak or they are clearly badly made in the beginning.

There is an older plastic system with brownish fittings possibly called "bartol" or similar and they have been significant in their number of split fittings.

Tony

 

[Softus]

I don't really think it's fair to compare a properly fitted pushfit joints which one day decides to spring itself of its own accord to a poorly fitted solder or compression joint.

I beg to differ. No pushfit fitting is capable of making the decision that you attribute to it. And if I come across any failed fitting, I make a point of understanding why it failed, not just using the occurrence to fuel an irrational prejudice.

Copper tube doesn't corrode if adequately protected, not in my lifetime anyway.

Does this mean that you agree that it does corrode when not adequately protected? Whether or not you agree, I've cut out plenty of copper pipe that was either corroded or eroded, so we appear to be living in entirely different realities.

It just looks cheap and nasty to me and screams DIY, normally forced round bends etc....be fair there aren't many plastic pipe jobs you walk into and think "wow that looks nice and professional", there may be some, but I have never seen any.

Every job I complete I look at it and think that it looks nice and professional, be it in copper or plastic, and solder, compression or pushfit.

Sorry but I stick with unproven, I have never seen 30 year old plastic pipe installations

You're never seen it so it doesn't exist - this doesn't give the impression of being a cogent conclusion.

...and the older stuff I have seen has all been un barriered and trashed the system which isn't a particulaly impressive track record.

OK, I get it now - you prefer copper, as long as it's been correctly installed and protected, over plastic that has not been correctly installed. Well whoop-de-doo.

Yes cheaper to install but as a fitting still overpriced.

It isn't cheaper to install, nor did I say that it was.

I have used it alot, but sorry in my opinion it is not a realistic substitute for copper.

You're not actually sorry though, are you. Nevertheless, you're entitled to your opinion, no matter how blinkered it is and even though it flies in the face of the facts.

 

[ollski]

Softus we could go round in circles over stupid, niggly little points, but my opinion is the same that plastic is rubbish and an opinion based on what I have seen in my experience is all I can give. You are perfectly welcome to do the same as others have and let the original poster draw his own conclusions. You may also wish to read others experiences with plastic on here although we will probably all be dismissed as blinkered and flying in the face of fact.