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?
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
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
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!
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.
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].
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.
On Wed, 8 Jun 2011 11:21:48 +0100, chris French wrote:
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.
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
I never had a problem with shaping and soldering copper pipe - but polypipe
just makes the whole job dramatically easier and simpler.
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.
My heating engineer only uses copper, and says many of his customers
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
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