Plastic piping for hot and cold plumbing.

I have had a nose round the Wiki and been reminded of the Dr. Drivel
days.

Any more current do's and don'ts? I have several runs to do which will
be very difficult in soldered 15mm copper. All the couplers can be in
accessible places but current views on pressure/water hammer/ couplings
etc. would be helpful.

The underfloor system will be 16mm pex al pex and the suppliers
helpfully say offcuts can be used for general plumbing purposes.
--
Tim Lamb

On Sat, 05 Aug 2017 09:26:53 +0100, Tim Lamb wrote:

Plastic piping for hot and cold plumbing.

I have had a nose round the Wiki and been reminded of the Dr. Drivel
days.

Any more current do's and don'ts? I have several runs to do which will
be very difficult in soldered 15mm copper. All the couplers can be in
accessible places but current views on pressure/water hammer/ couplings
etc. would be helpful.

The underfloor system will be 16mm pex al pex and the suppliers
helpfully say offcuts can be used for general plumbing purposes.

I have been using plastic pipe for over a decade without any issues of
failing couplings, water hammer etc.

SpeedFit, of course.

I did try some alternative couplings with those strange metal teeth built
in but they were a ******* to fit and even worse to take apart again. I
like the simple way the SpeedFit clamp on and then can be unclamped again
as you for example trial fit a run of pipe. Also useful for removing
things like shower pumps.

Main downside seems to be the reduced internal diameter compared to
copper, and some edge cases for fiddly runs where you can pre-solder
artistic copper sculptures then feed them through very tight spaces. The
fittings are more bulky than soldered copper as well.

Nice things include the bendiness so you can thread a single run of pipe
through and around various obstacles where you would be stuck bending and
jointing copper pipe.

I don't see pressure being an issue as I used plastic on the output side
of a powerful shower pump to feed two showers simultaneously. However no
idea what the peak pressure was.

Anyway, I am a confirmed fan.

YMMV.

Cheers


Dave R



--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

David wrote:

Also useful for removing things like shower pumps.

I had a shower pump where a (no-name) push fitting managed to remove itself.

Anyway, I am a confirmed fan.

Less of a fan, after I had to replace the sodden ceiling.

The replacement pump does have push fittings (22mm instead of 15mm, and
actual JG fittings rather than no-name) and no problems with it.

In message , Andy Burns
writes
David wrote:

Also useful for removing things like shower pumps.

I had a shower pump where a (no-name) push fitting managed to remove itself.

Anyway, I am a confirmed fan.

Less of a fan, after I had to replace the sodden ceiling.

The replacement pump does have push fittings (22mm instead of 15mm, and
actual JG fittings rather than no-name) and no problems with it.

Hmm.. So that is 2 moderately positive. The reduced bore may be an issue
as one of the runs is for a bath.

I'll do some more investigation on line.

--
Tim Lamb

On Sat, 05 Aug 2017 11:38:53 +0100, Tim Lamb wrote:


Hmm.. So that is 2 moderately positive. The reduced bore may be an issue
as one of the runs is for a bath.

I'll do some more investigation on line.

A 3rd moderately positive - moderately in that 10 days after fitting a
new electric shower unit the angle joint blew apart along its moulding
seam. That was on Christmas morning with guests staying over

I did have a replacement, fortunately, and the installation has now been
in use for around 10 years with no further problems.

Haven't got a clue now which brand I used though.

On 8/5/2017 2:30 PM, Mark Allread wrote:
On Sat, 05 Aug 2017 11:38:53 +0100, Tim Lamb wrote:


Hmm.. So that is 2 moderately positive. The reduced bore may be an issue
as one of the runs is for a bath.

I'll do some more investigation on line.

A 3rd moderately positive - moderately in that 10 days after fitting a
new electric shower unit the angle joint blew apart along its moulding
seam. That was on Christmas morning with guests staying over

I did have a replacement, fortunately, and the installation has now been
in use for around 10 years with no further problems.

Haven't got a clue now which brand I used though.


I'm a bit more than a moderate positive. I have had a couple of
failures, so your point about accessible couplings is good. My problems
were probably associated with inexperience and trying to get away with
the absolute minimum number of fittings, I am wiser now. Where you have
a nominally straight run between two complicated places, exactly as with
copper it is better to get each of the end bits right, and then join the
straight bits with one more (apparently redundant) connector.

They do make life *much* easier for long wiggly runs in old and much
modified properties.

When I started using it getting on for 30 years ago I put some in
exposed or semi-exposed runs too. I tend to use copper for things like
basins these days, this means you can be sure you have no strain and
perfect alignment on tap connectors. And copper for almost anything
which is going to be visible.

Not had a problem with reduced bore, but I plumbed the bath in 22 mm.

I've used mostly JG Speedfit.

On Saturday, 5 August 2017 09:27:35 UTC+1, Tim Lamb wrote:
The underfloor system will be 16mm pex al pex and the suppliers
helpfully say offcuts can be used for general plumbing purposes.

My German plumber rates pex-al-pex very highly and would use it for everything if he could.

Reduced bore for a bath is less of an issue if your hot water is mains pressure, and it reduces the amount of coled water that has to be run off before the hot comes through.

Owain

wrote in message
...
On Saturday, 5 August 2017 09:27:35 UTC+1, Tim Lamb wrote:
The underfloor system will be 16mm pex al pex and the suppliers
helpfully say offcuts can be used for general plumbing purposes.

My German plumber rates pex-al-pex very highly and would use it for
everything if he could.

Reduced bore for a bath is less of an issue if your hot water is mains
pressure, and it reduces the amount of coled water that has to be run off
before the hot comes through.

Owain


Another vote for Speedfit and plastic pipe. On moving into our 70's bungalow
ten years it became soon apparent we had a plumbing problem - all pipes were
unprotected copper in the screed, with various minor leaks, and very rapid
cooling of domestic hot water. Eventually I abandoned it all and replumbed
the whole house via the loft - hot and cold domestic water, plus central
heating, almost all in plastic . I've had no failures or leaks to date.

In a previous house I used H2O fittings - had two messy failures over an 8
year period, and not being able to easily demount was a pain by comparison
to Speedfit.

Observations:
1) A smear of silicone on the end of the pipes, as well as that already in
the fittings, helps a lot with assembly.
2) We are on mains pressure for hot and cold supplies, reduced from the
uncontrollable 10 bar incoming to 3.5 bar for the house and 5 bar for the
garden. With these pressures we get good flow rates from 15mm everywhere.
3) I stuck to Speedfit fittings throughout, but used different makes of pipe
at times. It became obvious that 15mm is the standard for the outer
diameter, but wall thicknesses vary, so buy pipe stiffeners with the pipe -
otherwise some will be too loose to have any effect. The only exceptions
used were some Flowplast 10mm adaptors, which leaked immediately, and were
then replaced with Speedfit, which didn't....
3) Speedfit fittings work fine on copper pipe, but if you demount them after
some years the O rings tend to stick to the copper. This doesn't happen with
plastic pipe. Re using the ones from copper seems to be OK, but I'm not sure
I'd want to do it too often. The alternative is to convert to copper with
compression fittings - works fine on plastic pipe.
4) Do all visible pipe runs in copper - it's impossible to get neat runs in
plastic because of the greater expansion and softness when hot.
5) We have one very long run in 15mm to a shower room right at one end of
the house - probably 20 metres. Waiting for hot water in the shower isn't
too bad, but the basin hot tap was painfully slow, esp in winter. In the end
I ran a parallel 10mm hot feed just for the basin hot tap, leaving the
shower on 15mm, and wait times are now quite sensible - and flow for a basin
tap is perfectly adequate, esp with the cold tap feed turned down to match.
6) I have one small underfloor heated room - a bathroom in a recent
extension. I bought a kit that used 16mm pipe, which worked fine, but I now
have a decent sized roll of 16mm pipe that I can't use - 15 to 16mm adaptors
don't seem to be at all easy to get. You can get the other bits for
underfloor heating in 15mm - so I'd suggest sticking to 15mm, whatever is
suggested by suppliers.

Go for it - it's faster, easier, and while you are half way through
plumbing it's very easy to make temporary connections to make parts of the
sytem work.

Charles F

On 8/5/2017 6:02 PM, Charles F wrote:

wrote in message
...
On Saturday, 5 August 2017 09:27:35 UTC+1, Tim Lamb wrote:
The underfloor system will be 16mm pex al pex and the suppliers
helpfully say offcuts can be used for general plumbing purposes.

My German plumber rates pex-al-pex very highly and would use it for
everything if he could.

Reduced bore for a bath is less of an issue if your hot water is mains
pressure, and it reduces the amount of coled water that has to be run
off before the hot comes through.

Owain


Another vote for Speedfit and plastic pipe. On moving into our 70's
bungalow ten years it became soon apparent we had a plumbing problem -
all pipes were unprotected copper in the screed, with various minor
leaks, and very rapid cooling of domestic hot water. Eventually I
abandoned it all and replumbed the whole house via the loft - hot and
cold domestic water, plus central heating, almost all in plastic . I've
had no failures or leaks to date.

In a previous house I used H2O fittings - had two messy failures over an
8 year period, and not being able to easily demount was a pain by
comparison to Speedfit.

Observations:
1) A smear of silicone on the end of the pipes, as well as that already
in the fittings, helps a lot with assembly.
2) We are on mains pressure for hot and cold supplies, reduced from the
uncontrollable 10 bar incoming to 3.5 bar for the house and 5 bar for
the garden. With these pressures we get good flow rates from 15mm
everywhere.
3) I stuck to Speedfit fittings throughout, but used different makes of
pipe at times. It became obvious that 15mm is the standard for the outer
diameter, but wall thicknesses vary, so buy pipe stiffeners with the
pipe - otherwise some will be too loose to have any effect. The only
exceptions used were some Flowplast 10mm adaptors, which leaked
immediately, and were then replaced with Speedfit, which didn't....
3) Speedfit fittings work fine on copper pipe, but if you demount them
after some years the O rings tend to stick to the copper. This doesn't
happen with plastic pipe. Re using the ones from copper seems to be OK,
but I'm not sure I'd want to do it too often. The alternative is to
convert to copper with compression fittings - works fine on plastic pipe.
4) Do all visible pipe runs in copper - it's impossible to get neat runs
in plastic because of the greater expansion and softness when hot.
5) We have one very long run in 15mm to a shower room right at one end
of the house - probably 20 metres. Waiting for hot water in the shower
isn't too bad, but the basin hot tap was painfully slow, esp in winter.
In the end I ran a parallel 10mm hot feed just for the basin hot tap,
leaving the shower on 15mm, and wait times are now quite sensible - and
flow for a basin tap is perfectly adequate, esp with the cold tap feed
turned down to match.
6) I have one small underfloor heated room - a bathroom in a recent
extension. I bought a kit that used 16mm pipe, which worked fine, but I
now have a decent sized roll of 16mm pipe that I can't use - 15 to 16mm
adaptors don't seem to be at all easy to get. You can get the other bits
for underfloor heating in 15mm - so I'd suggest sticking to 15mm,
whatever is suggested by suppliers.

Go for it - it's faster, easier, and while you are half way through
plumbing it's very easy to make temporary connections to make parts of
the sytem work.

Charles F


+1 to all that. Silicone spray is fine too, and perhaps slightly more
convenient. I will confess to having used WD40 or similar without
problems, IMHO the trace of mineral oil present would not be sufficient
to affect the O ring in the long term.

On 05/08/2017 09:26, Tim Lamb wrote:
Plastic piping for hot and cold plumbing.

I have had a nose round the Wiki and been reminded of the Dr. Drivel days.

Any more current do's and don'ts? I have several runs to do which will

Clean square pipe cuts are the main requirement. So pipe cutter on
copper and shears and then the recommended inserts on PEX

I have used several types over the years for various applications.
Speedfit have always been easy to use and reliable. Recently I used to
HeP20 and found that very good as well. The Hep20 is aesthetically a
little neater, but you need at tool to dismount a joint, whereas
speedfit you can undo by hand.

I have also used some floplast which I was less impressed with since its
difficult to get the pipe inserted correctly - especially when working
with any angle or offset close to the entry point.

I also used some cuprofit where I needed a quicj joint on visible copper
- again quite nice.

be very difficult in soldered 15mm copper. All the couplers can be in
accessible places but current views on pressure/water hammer/ couplings
etc. would be helpful.

Not had any problem with water hammer. I tend to use copper or chrome
for any show work. You will get some flow restriction but not much at
mains pressure. may be more of an issue on low pressure wide bore, but I
have not tried it in that circumstance.

The underfloor system will be 16mm pex al pex and the suppliers
helpfully say offcuts can be used for general plumbing purposes.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/