Andy,
Been away from my PC all weekend so just seen your post. Very valuable. Many
thanks.
Dave
"Andy Hall" wrote in message
...
On Sat, 25 Oct 2003 18:12:51 +0100, "David"
wrote:

Anyway back to the topic...
I still don't really understand the pros and cons of plastic over copper
piping.

Manufacturers of plastic systems are guaranteeing against defects in
manufacturing or materials for 50 years based on 20 years of actual
operational experience and probably accelerated life testing.

e.g.

http://www.hepworthplumbing.co.uk/BiTitesguide03.html

Manufacturers of copper products do not seem to do that but probably
because they do not feel a need to do so since the perception is that
they will have a very long lifetime.

In neither case do the manufacturers guarantee against defective
installation, and it is likely that this is the most common cause of
failure in both cases.

Plastic is generally rather quicker to install and the flexibility of
the pipe to bend through awkward places is helpful. It is more
expensive to buy than copper products, but the time saved may well
justify it.


For example:
How do you join it and is it easier to join and repair than copper and
are
the joints more trust worthy over time or not?

It really depends on who you are and how adept you are. Plastic
pipes are joined with couplers in the same way as copper pipes are.

With plastic, they are quick push fit fittings which require only the
proper pipe cutter to do a good job.

With copper, you have the choice of soldered copper in either end feed
(cheapest) or solder ring types; push fit or compression fittings.

For most people, learning to solder pipe fittings is not that
difficult and once a few have been done it is reasonably quick.
Most of the time is in cutting, bending and fitting the pipe.
Compression fittings are easy to work with but cost rather more.

As to trustworthiness, all types of joints are in essence mechanical
in nature, but implemented in different ways. The plastic system
manufacturers will argue that properly installed and under normal
operating conditions and with some margin, their fittings will stand
the test of time. The guarantees offered would tend to suggest that
they have done their homework. With the correct temperature and
pressure safety devices in place, plastic pipes will not be subjected
to conditions near their maximum ratings.



I guess an advantage would be that it might absorb acoustic noise better
than cooper but what are the negatives.

When hot water is carried, the plastic pipes do need to be supported
at more frequent positions or they will tend to sag.

I have not noticed that there is any appreciable difference as far as
noise is concerned.


The deterioration of copper over time is well known but what about
plastic
carrying hot water over, say, 20 years. Better or worse or as I suspect
not
proven.

There is about 20 years experience, which appears to be enough to make
manufacturers comfortable in offering 50 year guarantees. It would
be somewhat foolhardy to do that if they were not comfortable with the
supporting data.

It then depends on whether people are prepared to accept that and the
results of accelerated life tests or prefer to wait to see actual
operational experience.

As always, the likely deciders are going to be overall cost of
implementation by professional purchasers of the products.


This is the sort of factual information I was hoping to get and would be
grateful to receive good advise on .
Thanks again
Dave




"David" wrote in message
. ..
New to this forum so hope this is not OT.
I visited the site of a new house I am interested in buying which
hasn't
been completed and was really surprised to see that there seemed to be
"plastic" hoses for the water supply in the garage area where I would
have
suspected to see copper piping. I couldn't see what was used in the
rest
of
the house but is this really what builders are using these days??
This was not some cheap cheap place but what was described as a 5 bed,
3
bath exec home.
Anyone care to say if this is usual nowadays?
I'm surpassed its even legal.
Thanks
Dave




.andy

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