Plastic plumbing newbie advice

[Lobster]

I'm going to be replacing my shower valve soon. I know the old one was installed using plastic pipework, and this will need a bit of reconfiguring for the new valve (basically, with the current valve there are 90-deg elbow 15mm tap connectors on the feeds, and these will need changing to straight ones.

I've never used plastic tube before, but AFAICR it's important to use fittings which are compatible with the brand of tube, correct? Particularly inserts within the pipe? I have no clue what brand mine is (it's grey, 15mm) - maybe I'll find it printed on the pipe when I have it fully exposed?

Advice appreciated...

Thanks David

[TheOldFellow]

If it's grey, it is likely to be either Polyplumb or H2O, all but the very cheap pipe (eg some white floplast) has this info printed on it. The practical differences in pipe are mainly the inside bore, the outside will be 15mm for all of them. You can use most pushfit and compression fittings on any 15mm plastic tube, but the stiffener insert needs to be chosen to suit the inside bore, best to use the manufacturer's stiffener. You'll also need a pipe cutter so that you get clean 90 degree cuts on the ends - if you don't do much a cheap one will do.

It's worth remembering that while most plastic pipe comes in coils (25m to 100m long), but you can also get straight lengths of 2 or 3m. The straights make some things neater and easier. They still need inserts though!

R.

[chris French]

In message , TheOldFellow writes

John Guest also do a grey Speedfit pipe, but yes name should be on the pipe, you could probably also identify it by the fitting design. either by Googling up images or posting an image for others here to identify.

Yup, I've certainly mixed pipes and fittings before.

I've done a number of joints with a Stanley knife when my cutter went awol. It's fine as long as you are careful. Whilst a cutter is the right tool, if you are doing just a couple of joints I'd probably just do that

[Ret.]

When I replaced my bathroom 3 years ago I replaced all the piping to the bath, sink and shower with polypipe. I looked at a couple of proper pipe cutters but decided the cost was not worth it for a single job. I used a junior hacksaw and then cleaned up the cut ends with a Stanley knife (making sure no plastic swarf was left inside the pipe of course). The entire bathroom has been 100% watertight since I did the job!

[PeterC]

I used a copper pipe cutter to put a groove in the plastic pipe then used the SK, as this gives a followable mark to ensure a square end and also slightly rounds off the outside so that it goes in to the O-ring seal with no risk of damage.

[<me9]

Having struggled using similar methods in the past I purchased a pipe cutter from toolstation or screwfix for less than a tenner before replacing a basin last year. Worth it just for the one job, it must have reduced the time taken by at least half an hour compared with cruder methods, and did a better job. It has been used for several other jobs since.

The price of tools at the moment it's worth investing the odd beer token or two in tools. It makes DIY so much easier than it was.

[Roger Mills]

You'd make a good mate for Drivel then!

Whatever else you may do to plastic pipe, *don't* cut it with a hacksaw. In the absence of a proper cutter, a decent pair of by-pass (*not* anvil type) garden secateurs makes a good substitute.

The slightest roughness or burr on the outside will bugger up the O-ring of a push-fit fitting - which will then leak like a sieve. [Not quite so critical if you're using compression fittings].

[Lobster]

Thanks everyone all the info; that's reassuring. Hopefully when I expose the pipework fully it'll be clear what brand I've got and I can take it from there.

Cheers David

[Ret.]

[Ret.]

I agree with what you say about the roughness - which is why, having cut the pipe to the required length with a hacksaw, I then cut off a further 1-2mm of the rough-cut end with a Stanley knife which completely removes all roughness or burr from the end of the pipe.

[Ret.]

I often wonder what professional plumbers think of polypipe. It's no doubt made their job much easier - but also increased the opportunity for even the worst DIYer to do an effective plumbing job and avoid the need for a professional.

I never had a problem with shaping and soldering copper pipe - but polypipe just makes the whole job dramatically easier and simpler.

[sm_jamieson]

Do all plumbers use polypipe now, or offer 2 different prices, since it must be much quicker to use plastic? Its not the soldering of copper that really takes the time, but the bending etc. Must admit I still use all copper. Simon.

[dom]

My heating engineer only uses copper, and says many of his customers demand it.

In old buildings, with pipework hidden in voids, mice may be attracted to knaw on plastic pipe & fittings.

Personally, I use copper where it's exposed, where it has to support fittings (valves, pumps etc), or anywhere it's not in well-sealed cavities.

[Steve Firth]

Kevin Loon (ret) is an ideal mate for Drivel.

They are both pillocks.

[Ret.]

Do you *ever* have anything useful to add to a thread?

-- Kev

[Man at B&Q]

If you already have a copper pipe cutter, that will do fine.

MBQ

[Man at B&Q]

Why faff about? Just go all the way through with the copper pipe cutter.

MBQ

[PeterC]

a). it takes a long time for that thickness b). it bends in the inside of the pipe, making it more difficult to insert the, er, inserts that need, um, inserting.