I don't have a problem. Am just curious.

In my previous ex-LA house the central heating pipes were mainly
visible along the skirting boards and were also routed upstairs under
the floorboards. It was possible therefore to inspect the piping for
leaks quite easily.

In my current house, built in 2004, all piping is hidden under the
tiled floors. Only the little stubs that pop up through the floor
tiling where the radiators connect are visible.

Question: When such piping is installed, is it pressure tested in some
way? I could imagine discovering where a leak is with hidden piping
could be a very costly business. One would have to lift some or all of
the floor tiles for a start.

MM

On Tue, 15 Dec 2009 16:58:42 +0000, MM wrote:

I don't have a problem. Am just curious.

In my previous ex-LA house the central heating pipes were mainly
visible along the skirting boards and were also routed upstairs under
the floorboards. It was possible therefore to inspect the piping for
leaks quite easily.

In my current house, built in 2004, all piping is hidden under the
tiled floors. Only the little stubs that pop up through the floor
tiling where the radiators connect are visible.

Question: When such piping is installed, is it pressure tested in some
way? I could imagine discovering where a leak is with hidden piping
could be a very costly business. One would have to lift some or all of
the floor tiles for a start.

MM

Pipes under floorboards is bad enough but I never did like the idea of
under tiling ...

On Tue, 15 Dec 2009 16:58:42 +0000, MM wrote:

I don't have a problem. Am just curious.

In my previous ex-LA house the central heating pipes were mainly
visible along the skirting boards and were also routed upstairs under
the floorboards. It was possible therefore to inspect the piping for
leaks quite easily.

In my current house, built in 2004, all piping is hidden under the
tiled floors. Only the little stubs that pop up through the floor
tiling where the radiators connect are visible.

Hmm, if it's rads rather than UFH, could they not have used flexible pipe
and slid it into larger pipes embedded into the floor? That way if
something does ever cock up it might at least be possible to fix without
ripping the whole floor up...

The Water Regulations (or rather WRAS, the advisory scheme) have a
recommended procedure for pressure testing of supplies. ISTR though
that although some sort of pressure testing is mandatory in commercial
environments, it isn't on domestic installations.

Building Regulations mandate pressure testing of sewers, but not water
supply IIRC.

However pressure testing is widely used by professional plumbers, and
particularly for UFH.

A suitable gauge for dry air testing with a 15mm push fit on it is now
about 30 quid (http://www.screwfix.com/prods/72940/...ools/Plumbing-
Tools/Pressure-Test-Equipment/Monument-Dry-Pressure-Test-Kit).

I use one along with a car tyre footpump. It's not foolproof. I just
had to tackle an inaccessible joint with a very slow drip on it, that
didn't show under air testing. (My one and only poor solder joint in a
thermal store installation). But it will show most problems.

Possibly the much higher pressure, professional test kits will show
even the slightest leaks up.

(As an aside, when I used to work on ultra-high vacuum systems years
ago, mass-spectrometer gas analysers had just become available. You
connected up your vacuum system to the gas analyser, then went round
squirting helium gas at each joint, until the analyser showed up that
the gas had found a way inside the vacuum system - I don't think
plumbers have these *yet*)

On Tue, 15 Dec 2009 16:58:42 +0000, MM wrote:

Question: When such piping is installed, is it pressure tested in some
way? I could imagine discovering where a leak is with hidden piping
could be a very costly business. One would have to lift some or all of
the floor tiles for a start.

It should be. TBH if the mains is about 3.5 bar I usually just crank it up
to mains pressure and leave it for several hours.

--
John Stumbles -- http://yaph.co.uk

I am neither for nor against apathy

In article ,
" writes:
The Water Regulations (or rather WRAS, the advisory scheme) have a
recommended procedure for pressure testing of supplies. ISTR though
that although some sort of pressure testing is mandatory in commercial
environments, it isn't on domestic installations.

Building Regulations mandate pressure testing of sewers, but not water
supply IIRC.

However pressure testing is widely used by professional plumbers, and
particularly for UFH.

A suitable gauge for dry air testing with a 15mm push fit on it is now
about 30 quid (http://www.screwfix.com/prods/72940/...ools/Plumbing-
Tools/Pressure-Test-Equipment/Monument-Dry-Pressure-Test-Kit).

I use one along with a car tyre footpump. It's not foolproof. I just
had to tackle an inaccessible joint with a very slow drip on it, that
didn't show under air testing. (My one and only poor solder joint in a
thermal store installation). But it will show most problems.

Dry pressure testing works very well on systems which have never
had water in them. Can be much more touch and go on a system once
it's been wetted. Water can block leaks for long enough that you
won't find them. Depends on pipe layout and nature of the leak.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Tue, 15 Dec 2009 11:58:33 -0600, Jules
wrote:

On Tue, 15 Dec 2009 16:58:42 +0000, MM wrote:

I don't have a problem. Am just curious.

In my previous ex-LA house the central heating pipes were mainly
visible along the skirting boards and were also routed upstairs under
the floorboards. It was possible therefore to inspect the piping for
leaks quite easily.

In my current house, built in 2004, all piping is hidden under the
tiled floors. Only the little stubs that pop up through the floor
tiling where the radiators connect are visible.

Hmm, if it's rads rather than UFH, could they not have used flexible pipe
and slid it into larger pipes embedded into the floor? That way if
something does ever cock up it might at least be possible to fix without
ripping the whole floor up...


It's not UFH. It's standard copper tubing feeding radiators. I am
assuming that enough care is taken during the pipework installation to
give the pipework the longest life possible. As I see it, the ONLY
long-term threats to the pipework could be: structural movement, e.g.
earth tremor, settlement; or freezing; or corrosion. Otherwise the
pipes should surely last indefinitely without risk of leaking?

In my previous house, if there had been a leak it would have been
relatively trivial to repair, given the visibility of and easy access
to the pipework. This wouldn't be the case in my present property. By
the way, if I had the choice, I'd rather have the pipework on the
surface! Make it a design feature, perhaps. My next property is going
to be really old and I shall make a point to find one with open
pipework.

MM

On Tue, 15 Dec 2009 12:00:05 -0800 (PST)
" wrote:

The Water Regulations (or rather WRAS, the advisory scheme) have a
recommended procedure for pressure testing of supplies. ISTR though
that although some sort of pressure testing is mandatory in commercial
environments, it isn't on domestic installations.

Building Regulations mandate pressure testing of sewers, but not water
supply IIRC.

However pressure testing is widely used by professional plumbers, and
particularly for UFH.

A suitable gauge for dry air testing with a 15mm push fit on it is now
about 30 quid (http://www.screwfix.com/prods/72940/...ools/Plumbing-
Tools/Pressure-Test-Equipment/Monument-Dry-Pressure-Test-Kit).

I use one along with a car tyre footpump. It's not foolproof. I just
had to tackle an inaccessible joint with a very slow drip on it, that
didn't show under air testing. (My one and only poor solder joint in a
thermal store installation). But it will show most problems.

Possibly the much higher pressure, professional test kits will show
even the slightest leaks up.

(As an aside, when I used to work on ultra-high vacuum systems years
ago, mass-spectrometer gas analysers had just become available. You
connected up your vacuum system to the gas analyser, then went round
squirting helium gas at each joint, until the analyser showed up that
the gas had found a way inside the vacuum system - I don't think
plumbers have these *yet*)

When installing UFH I decided to invest in a wet pressure tester. It
cost £90, but I thought that cheap compared with a leak after
screeding. The procedure suggested was to fill the pipework with
water, connect up the pressure tester and take it up to 8 bar. Leave it
for 30 minutes, if no pressure drop, reduce the pressure to 6 bar and
leave it a further 24 hours. In fact I left mine at 6 bar for over a
week while the screed was laid and set - to protect against labourer's
boots. Overkill, yes, but the peach of mind....

R.

On Wed, 16 Dec 2009 08:37:43 +0000, MM wrote:

It's not UFH. It's standard copper tubing feeding radiators. I am
assuming that enough care is taken during the pipework installation to
give the pipework the longest life possible. As I see it, the ONLY
long-term threats to the pipework could be: structural movement, e.g.
earth tremor, settlement; or freezing; or corrosion. Otherwise the
pipes should surely last indefinitely without risk of leaking?


The main "long-term threat to the pipework" will be from the constant
expansion and contraction of the pipes in normal operation as the
boiler starts up and circulates the hot water, forcing the pipes to
expand, then stops and allows the pipes to contract as they cool down.

It is extremely rare for plain pipe to leak. The leaks will normally
come at joints and fittings where the expansion and contraction of the
pipes place quite high stresses on both soldered and mechanical
joints.

There will also be some corrosion between the dissimilar metals used,
although this can be kept to a minimum by use of a corrosion inhibitor
in the system.

On 15 Dec, 20:00, " wrote:

However pressure testing is widely used by professional plumbers, and
particularly for UFH.

A suitable gauge for dry air testing with a 15mm push fit on it is now
about 30 quid (http://www.screwfix.com/prods/72940/...ools/Plumbing-
Tools/Pressure-Test-Equipment/Monument-Dry-Pressure-Test-Kit).

I use one along with a car tyre footpump. It's not foolproof. I just
had to tackle an inaccessible joint with a very slow drip on it, that
didn't show under air testing. (My one and only poor solder joint in a
thermal store installation). But it will show most problems.

Only a knob tests systems with air. It goes bang if it fails and bits
of metal & plastic may fly around at terminal velocities, i.e., it
will terminate you if you're in the way.

One of the aims of the test is to force any weak joint to fail, then
it is not a good idea, i.e. a system failure under a pressure test is
a sucessful pressure test. . Since many fittings are made by no-name
manufacturers in far eastern sweat shops with no quality control,
putting such fittings under air pressure really is not a good idea.

The HVCA recommendation is to test with water if at all possible. If
pneumatic testing is unavoidable. then the recommendations are
onerous, e.g., evacuate areas under test, no more than 0.5 bar
pressure, tie down hoses, calibrated pressure gauge, board over
windows, etc.. You deviate from these recommendations at your peril
(and you needlessly endanger anyone in the vicinity).

Water testing will show a leak far quicker than air. A competent
plumber would have no qualms in filling a new system with water
because he should be confident that there will be no leaks.

Helium leak detectors are used but only by leak detection
contractors.

On Wed, 16 Dec 2009 08:37:43 +0000, MM wrote:

I am assuming that enough care is taken during the pipework installation
to give the pipework the longest life possible.

Bad assumption. Time is money to builders. To do things with full
care and attention to detail takes lots of time...

--
Cheers
Dave.

On Wed, 16 Dec 2009 09:37:00 +0000, Bruce
wrote:

It is extremely rare for plain pipe to leak. The leaks will normally
come at joints and fittings where the expansion and contraction of the
pipes place quite high stresses on both soldered and mechanical
joints.

This immediately makes me ask whether the pipe runs under the flooring
are continuous without joins?

MM

On Wed, 16 Dec 2009 11:57:43 +0000 (GMT), "Dave Liquorice"
wrote:

On Wed, 16 Dec 2009 08:37:43 +0000, MM wrote:

I am assuming that enough care is taken during the pipework installation
to give the pipework the longest life possible.

Bad assumption. Time is money to builders. To do things with full
care and attention to detail takes lots of time...

Which is, I am given to understand by the neighbours, what happened.
These houses are NOT the bad kind that feature on those "Watchdog"
type programmes on the TV. They were built by a local builder who is
currently building other houses in the immediate area.

MM

MM wrote:
Otherwise the
pipes should surely last indefinitely without risk of leaking?
No, mine have started to leak after ~17 years :-(.

In article o.uk,
"Dave Liquorice" writes:
On Wed, 16 Dec 2009 08:37:43 +0000, MM wrote:

I am assuming that enough care is taken during the pipework installation
to give the pipework the longest life possible.

Bad assumption. Time is money to builders. To do things with full
care and attention to detail takes lots of time...

Yep - that's the sort of thing you'll see in a DIY install.
My dad did exactly this when planning the pipework for his
solid floor extention. All the pipework runs are short
enough that there are no joins under the floor. (Mind you,
that is easier with a single-pipe system.)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]