Plastic vs copper pipework

[Joe the plumber]

I've looked around a number of used narrowboats recently with a view to buying one in due course should our forthcoming week's holiday prove successful.

 

I've noticed that most of them have their water and central heating pipework in plastic (PolyPipe, Speedfit or similar) rather than the traditional copper, and wondered if this was for a particular reason.

 

I thought perhaps it was because there was less chance of vibration fracturing plastic pipes, but having had what I hope is a thorough search on here, I've not found an answer. Can anyone help please?

 

Apologies if it's been covered before, but thanks for any replies folks.

[W+T]

Hi there, i would use it as its easy to use, as in `speed fit` no heat needed, does resist freezing temps unlike copper which can burst/split. thats enough for me.

Edited September 12, 2015 by W+T

[Traveller]

Hi there, i would use it as its easy to use, as in `speed fit` no heat needed, doesnt resist freezing temps unlike copper which can burst/split. thats enough for me.

 

+1

[RLWP]

+2

 

Our house is piped up in it too

 

Richard

[John V]

The main part of my CH system is copper because it was what was used 20 years ago, the additional pipework that I have been adding over the last week or so is plastic Price/convenience/minimum joints in a run.

[nicknorman]

Yup plastic is just so much easier. There are a few places where you are supposed to use copper for a bit eg the outlet of central heating boilers etc. I guess that is in case it overheats or perhaps gets hotter just after shutdown when the circulating pump is stopped.

[koukouvagia]

When I first started plumbing in boats I used copper fittings which I soldered; then came pre-soldered copper fittings; then compression fittings; then push-on copper fittings. Speedfit plastic fittings are the natural evolution. I wouldn't dream of turning back the clock.

The only disadvantage is aesthetic. I have to admit that copper pipe and fittings look much better in a cabin.

[Bee]

I used plastic hose (not garden hose) from ASAP supplies as the pipe runs were so convoluted, no problems in 8 years except that as we only use the moat for 6 months a year the first few gallons have to be run off as the tea tastes horrible.

[magnetman]

...we only use the moat for 6 months a year....

I guess you use the drawbridge in winter then?

 

 

 

I like speedfit stuff its so convenient. When I did a central heating system with 28mm I used copper as it was visible but for anything small and/or concealed speedgit is ideal.

[starman]

Plastic every time; so much easier and quicker. Used it in house as well as on boat. Just make sure the pipe inserts are fitted and the pipes pushed firmly home into the joints. I only use copper where you have to - eg near heat sources like boilers - and where it shows in cabin.

[jaywalker]

As a plumber of a certain age, might I say I detest platic pipe with a passion.

It is for DIYers and people who cant solder properly.

What did I use on my boat? Plastic pipe and pushfit fitings it is a no-brainer, just use loads of clips and hide as much as you can.

[Neil2]

One of the the main advantages of plastic in a boat, especially if you are retro fitting, is the facility to bend long pipe runs.

 

But freezing can be more catastrophic. Copper pipe tends to puncture but water freezing in plastic pipe usually blows the joints apart.

[zimzim]

Plastic very fast and convenient - flexible to install in awkward shaped spaces, and you don't need to go in with the soldering iron, so safer, and much less faff.

Also easier to disconnect/uninstall, when you want to change things, or have messed up!

Like previous posters, I always use copper where visible or near to heat sources.

Remember to use lubricant gel (!)

Always use a quality brand (I use Hep2o or Speedfit) - cheap ones do not age well - especially when subject to repeated/prolonged cycles of high temperatures and cooling.

Never put your finger inside the fitting (or let kids) - there are metal teeth in there designed to grip the end of the pipe!

 

I must admit, I still like the permanency of soldered copper, when the access is good and time is not pressing.

[Tony Brooks]

There are some fittings that are not readily available in plastic like 22mm Lever Ball Valves but are available in compression. My advice would be to always use metal inserts in the plastic pipe where you intend to use a compression fitting. The plastic inserts seem to collapse under the olive so you can not get them to seal.

[peterboat]

There are some fittings that are not readily available in plastic like 22mm Lever Ball Valves but are available in compression. My advice would be to always use metal inserts in the plastic pipe where you intend to use a compression fitting. The plastic inserts seem to collapse under the olive so you can not get them to seal.

Bugger I have used plastic inserts on some compression joints they havent leaked yet..................................

[Ally]

We used nearly all copper for our boats, with just small stretches of plastic for quieter running from pumps for example, returning to copper after a short run. Lasts well, looks better, neater work, but very definitely more expensive! But we preferred it to all plastic.

[canals are us?]

My gravity solid fuel central heating is all 28mm,22mm and 15mm copper due to neatness and an uncontrolled heat source.

The hot and cold water runs are all plastic. I think it looks ugly and fittings bulky. Most is hidden so no problem. I think both has there plusses and minuses as said. I do find plastic much quicker but my first experience of plastic wasn't great when I plumbed a bungalow and a rodent chewed through the pipe enough to cause a damp patch. Chewed the lagging and nicked the hot water pipe. Repaired with compression coupler and threw down sachets.

 

James

Edited September 13, 2015 by canals are us?

[Joe the plumber]

Thanks for all the replies folks.

 

Just like in the modern building trade, it seems then it's primarily fitted for ease of use and cheapness, not because of any particular failing with copper.

 

I'm with Jaywalker in my opinion of it from my professional point of view, but I can understand why it's so popular. It will be interesting to see if, in future, it's just as fragile as the 'Polyork' pipes that were used in the mid-1970s in many houses.

[magnetman]

That's an interesting point.

 

As an example my boat is 18 years old and was originally plumbed with grey "Hep2o" pipe and fittings which are mainly hidden behind lining. Does this stuff have a fixed lifetime?

 

Will there be a point when it all starts degrading

Bearing in mind I intend to keep this boat for another 30 years

 

I suppose it hasn't been around long enough to find out

[Joe the plumber]

Push fit fittings rely on 'O' rings to form a watertight seal and I assume they degrade over time, so that might be the achilles heel of it. Polyork was glued together and is more like the old Airfix kit plastic, but it does become very brittle.

 

I don't know what the modern pipe is made from, but it's certainly not the same as Polyork. I often find UPVC waste pipework that's exposed to sunlight disintigrates after it's perhaps 15-20 years old, but that may be a different material too.

 

All modern plastic pipe seems to have a 25 year guarantee, but as you say, it's not that old yet, so who knows.

 

I sometimes come across copper pipes that have corroded through from the inside if they have some form of contaminant (eg a small particle of another metal) sitting in them, but then I've worked in houses with copper pipes from the 1920s that are still sound. It's usually the brass fittings that degrade first with those.

[John V]

I'm not certain (and if I'm wrong I am sure someone will be along to correct) I believe the modern plastic pipe is three layers of different plastics....one of which at least is XLPE (cross linked polyetheline) which is extremely tough and stable

[Murflynn]

I guess you use the drawbridge in winter then?

 

 

 

I like speedfit stuff its so convenient. When I did a central heating system with 28mm I used copper as it was visible but for anything small and/or concealed speedgit is ideal.

not a reference to a certain lady power-boater of this forum I hope?

[Neil2]

My gravity solid fuel central heating is all 28mm,22mm and 15mm copper due to neatness and an uncontrolled heat source.

The hot and cold water runs are all plastic. I think it looks ugly and fittings bulky. Most is hidden so no problem. I think both has there plusses and minuses as said. I do find plastic much quicker but my first experience of plastic wasn't great when I plumbed a bungalow and a rodent chewed through the pipe enough to cause a damp patch. Chewed the lagging and nicked the hot water pipe. Repaired with compression coupler and threw down sachets.

 

James

 

That's a good point, though not really a consideration on a boat, rodents do like to nibble away at plastic pipe. They have been known to chew through copper as well but that's quite rare.

 

My experience of water pipes comes from living next door to a retired plumber and doing flood damage work for ten years (the two are not related). My mate next door would never, ever, tolerate plastic under any circumstances and said you should never employ a plumber who suggested using it. My flood damage experience suggests plastic pipe is more likely to be the cause of water damage than copper.

 

I too wonder about degradation of plastic but again not likely to be an issue on a boat, and in that environment I think the advantages of flexible pipe outweigh any disadvantages. I wouldn't use it in a house though.

[blackrose]

Bugger I have used plastic inserts on some compression joints they havent leaked yet..................................

 

Me too!

[Joe the plumber]

For interest, I'm now almost there with fitting an Eberspacher D4WSC kit on our boat (we didn't have a boat when I started this topic) and I've plumbed all the radiators in 22mm copper (the instructions say to use 22mm pipe) with 15mm tails to the valves (again, as per the instructions). All this is visible in the boat so plastic would have looked ghastly.

 

I've designed the system to be a two pipe reverse return set up, which means the radiators won't need balancing as they're all the same distance from the boiler. The only disadvantage is I've got three large pipes running under the rads rather than two for the usual system, but it also means more pipes to help to heat the boat, so it's not a bad thing.

 

I'm currently debating whether to complete the job in copper, just using the flexible hoses supplied in the kit to attach it to the inlet and outlet on the boiler (where you couldn't use copper or plastic pipe anyway).

 

Having said all that, the calorifier circuit will be in plastic, but that's not on show.