Oh dear!
The pipes went down and were tested as not leaking.
The screed went down dry and no leaks showed up.
The floorsheets went down and then the ply and ceramic tiles.
And then the plumber came to connect the manifold to the boiler.

and we discovered we have a leak somewhere under the floor which wasn't
there when the screed went down.

Aaaaaargh!

The conservatory floor is downstairs and is a suspended wooden floor
with kingspan between the joists supported by slats between the joists
with the pipes and screed laid on top of that but between the joists.
The floor sheets rest on the joists and have been screwed in.
The ply has been screwed to the floor sheets. The tiler asked how thick
the floor sheets were to ensure that the screws he used didn't go right
through.
The only access to the under floor void is through the air bricks.

Is there any way we can :
a) plug the hole in the pipe without disturbing the tiles? Radweld
springs to mind but I have a feeling it might break the boiler. I'm
assuming that the
b) if a) is not possible can we find out where the pipe is leaking
without ripping up the whole floor (is there some detector that works
through the tiles (eg by measuring microwave absorbtion or something).
Is it possible to remove just a portion of the tiled floor without
disturbing the surrounding tiles??

Any suggesstions welcome as we really don't want to start all over again!

Despontantly

Chris J

ChrisJ wrote:

and we discovered we have a leak somewhere under the floor which wasn't
there when the screed went down.

Myself, I'd be tempted to try some of that CH leak sealant liquid you
put in the system then allow to circulate.

It's sorted me out on one occasion.
I bet a screw has gone through a pipe!

Is pressure dropping rapidly of is it over the course of rays rather
than minutes?


--
http://gymratz.co.uk - Best Gym Equipment & Bodybuilding Supplements UK.
http://trade-price-supplements.co.uk - TRADE PRICED SUPPLEMENTS for ALL!
http://fitness-equipment-uk.com - UK's No.1 Fitness Equipment Suppliers.
http://Water-Rower.co.uk - Worlds best prices on the Worlds best Rower.

ChrisJ wrote:
Oh dear!
The pipes went down and were tested as not leaking.
The screed went down dry and no leaks showed up.
The floorsheets went down and then the ply and ceramic tiles.
And then the plumber came to connect the manifold to the boiler.

and we discovered we have a leak somewhere under the floor which
wasn't there when the screed went down.

Aaaaaargh!

The conservatory floor is downstairs and is a suspended wooden floor
with kingspan between the joists supported by slats between the joists
with the pipes and screed laid on top of that but between the joists.
The floor sheets rest on the joists and have been screwed in.
The ply has been screwed to the floor sheets. The tiler asked how
thick the floor sheets were to ensure that the screws he used didn't
go right through.
The only access to the under floor void is through the air bricks.

Is there any way we can :
a) plug the hole in the pipe without disturbing the tiles? Radweld
springs to mind but I have a feeling it might break the boiler. I'm
assuming that the
b) if a) is not possible can we find out where the pipe is leaking
without ripping up the whole floor (is there some detector that works
through the tiles (eg by measuring microwave absorbtion or something).
Is it possible to remove just a portion of the tiled floor without
disturbing the surrounding tiles??

Any suggesstions welcome as we really don't want to start all over
again!

Despontantly

Chris J

One of the pitfalls of laying piping under floor tiles/laminate ect ect.
:-(
Glad my piping is behind skirting. :-)

--
Sir Benjamin Middlethwaite

Pet @ www.gymratz.co.uk ;¬) wrote:

ChrisJ wrote:

and we discovered we have a leak somewhere under the floor which
wasn't there when the screed went down.


Myself, I'd be tempted to try some of that CH leak sealant liquid you
put in the system then allow to circulate.

It's sorted me out on one occasion.
I bet a screw has gone through a pipe!

Is pressure dropping rapidly of is it over the course of rays rather
than minutes?


My thoughts too. I hope the floorer and tile have good insurance or are
willing to redo it all for a four pack of beer!

The pressure drops within about 30 minutes. We've isolated the manifold
from the rest of the CH and the leak is definately there or under the floor.

ChrisJ

ChrisJ wrote:
Oh dear!
The pipes went down and were tested as not leaking.
The screed went down dry and no leaks showed up.
The floorsheets went down and then the ply and ceramic tiles.
And then the plumber came to connect the manifold to the boiler.

and we discovered we have a leak somewhere under the floor which
wasn't there when the screed went down.

Any suggesstions welcome as we really don't want to start all
over again!

Bad luck, that must be so annoying.

Have you considered abandoning the UFH and installing conventional rads?

ChrisJ wrote:

Pet @ www.gymratz.co.uk ;¬) wrote:

ChrisJ wrote:

and we discovered we have a leak somewhere under the floor which
wasn't there when the screed went down.



Myself, I'd be tempted to try some of that CH leak sealant liquid you
put in the system then allow to circulate.

It's sorted me out on one occasion.
I bet a screw has gone through a pipe!

Is pressure dropping rapidly of is it over the course of rays rather
than minutes?


My thoughts too. I hope the floorer and tile have good insurance or are
willing to redo it all for a four pack of beer!

The pressure drops within about 30 minutes. We've isolated the manifold
from the rest of the CH and the leak is definately there or under the
floor.

ChrisJ

Just been reading up and have found that fernox do a raditor leak fixer
for fixing inaccessible leaks. Would this work in the plastic UFH pipe?
Are these fixes generally permanent or is it a bodge that will need
repeated fernox applications? I'm presuming we have a screw through the
pipe or at least into it.

Its a presurised combi boiler. How would I get the fernox in?

ChrisJ

Any suggesstions welcome as we really don't want to start all over again!

Despontantly

Chris J

How much space is there under the floor? Could you remove a few bricks
and crawl in?
Another long shot is a stethoscope. Put as much pressure on the system
as possible and follow the route listening. you may get lucky.
Personally I wouldn't trust leak sealer on plastic pipe. The sealer is
unlikelt to stick to the plastic and as the plastic flexes it any
deposit is likely to crack off.

Good luck

John

ChrisJ wrote:
Oh dear!
The pipes went down and were tested as not leaking.
The screed went down dry and no leaks showed up.
The floorsheets went down and then the ply and ceramic tiles.
And then the plumber came to connect the manifold to the boiler.

and we discovered we have a leak somewhere under the floor which wasn't
there when the screed went down.


Having fitted UFH .. you let a tradesman screw to the floor ? ...
lesson learned the hard way.

The fix is to expose the portion with the leak ...cut out the damaged
portion and fix with a repair fitting.
Probably not what you wanted to know ..

ChrisJ wrote:

b) if a) is not possible can we find out where the pipe is leaking
without ripping up the whole floor (is there some detector that works
through the tiles (eg by measuring microwave absorbtion or something).

Perhaps adding a flourescent dye as used by aircon installers may help.
If you can shine some UV light into the void afterwards you may see
where it was leaking.

Is it possible to remove just a portion of the tiled floor without
disturbing the surrounding tiles??

Yes, How you do it will depend on the type of tiles. A Fein multimaster
can take out individual tiles neatly if required (although not withoy
damaging the removed tiles). A trend routabout cutter can be used to
make a neat access hole to the floor void if required after.

--
Cheers,

John.

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

On Fri, 16 Jun 2006 18:51:57 +0100, ChrisJ
wrote:

Oh dear!
The pipes went down and were tested as not leaking.
The screed went down dry and no leaks showed up.
The floorsheets went down and then the ply and ceramic tiles.
And then the plumber came to connect the manifold to the boiler.

and we discovered we have a leak somewhere under the floor which wasn't
there when the screed went down.

Aaaaaargh!

The conservatory floor is downstairs and is a suspended wooden floor
with kingspan between the joists supported by slats between the joists
with the pipes and screed laid on top of that but between the joists.
The floor sheets rest on the joists and have been screwed in.
The ply has been screwed to the floor sheets. The tiler asked how thick
the floor sheets were to ensure that the screws he used didn't go right
through.
The only access to the under floor void is through the air bricks.

Is there any way we can :
a) plug the hole in the pipe without disturbing the tiles? Radweld
springs to mind but I have a feeling it might break the boiler. I'm
assuming that the
b) if a) is not possible can we find out where the pipe is leaking
without ripping up the whole floor (is there some detector that works
through the tiles (eg by measuring microwave absorbtion or something).
Is it possible to remove just a portion of the tiled floor without
disturbing the surrounding tiles??

Any suggesstions welcome as we really don't want to start all over again!

Despontantly

Chris J


The stethescope idea sounds good, maybe compressed air (used with
great care) would make better noise for detection.

Something I'd try...

Suck/blow a small bit of rag on fine fishing line all the way through
using a vac.

IF this works then pull stronger line and then a ball that is a fairly
snug fit through (keeping the line at both ends).

If it jams at some point, that's where a screw is. Try it from the
other end to double check.

Maybe then pull some fine wire through attached to the line from where
the ball is, connect to isolated 240v (shaver transformer) and use a
cable detector above to trace where it stops.

Good luck!!!

cheers,
Pete.

On Fri, 16 Jun 2006 18:51:57 +0100, ChrisJ
wrote:

Oh dear!
The pipes went down and were tested as not leaking.
The screed went down dry and no leaks showed up.
The floorsheets went down and then the ply and ceramic tiles.
And then the plumber came to connect the manifold to the boiler.

and we discovered we have a leak somewhere under the floor which wasn't
there when the screed went down.

Aaaaaargh!

The conservatory floor is downstairs and is a suspended wooden floor
with kingspan between the joists supported by slats between the joists
with the pipes and screed laid on top of that but between the joists.
The floor sheets rest on the joists and have been screwed in.
The ply has been screwed to the floor sheets. The tiler asked how thick
the floor sheets were to ensure that the screws he used didn't go right
through.
The only access to the under floor void is through the air bricks.

Is there any way we can :
a) plug the hole in the pipe without disturbing the tiles? Radweld
springs to mind but I have a feeling it might break the boiler. I'm
assuming that the
b) if a) is not possible can we find out where the pipe is leaking
without ripping up the whole floor (is there some detector that works
through the tiles (eg by measuring microwave absorbtion or something).
Is it possible to remove just a portion of the tiled floor without
disturbing the surrounding tiles??

Any suggesstions welcome as we really don't want to start all over again!

Despontantly

Chris J


One other idea if a line can't be pulled through, blow a close fitting
steel ball though with water, if it gets stuck use a metal detector to
find where...

cheers,
Pete.

ChrisJ wrote:
ChrisJ wrote:
and we discovered we have a leak somewhere under the floor which
wasn't there when the screed went down.

The only technique I know of for detecting leaks in UFH uses helium.
I've never had to use it (touch wood) and so don't know the details of
how it works. There used to be a technical paper available on the US
Radiant Panel Association (heating contractors') website called "Leak
Detection with Helium", but it's now only accessible to RPA members. If
you get details, I think you'll find it's a specialist process. Helium
is used as a tracer gas for leak detection 'cos the molecules are small
& will pass through small perforations.

It's used to find leaks in some duct/pipe systems in conjunction with
a forward light-scattering photometer, so it may be the same method
that's used for refrigerant systems. There's probably a BS on this(?).
Advise me if this looks promising & I'll have a rummage in the BS
catalogue on Monday.

The only other system I've used utilised compressed air; the air leaks
generate ultrasonic noise which are normally inaudible but could be
detected with a microphone/transducer/ headphones/amplifier type
device. Although effective with exposed pipes, I doubt this would work
through a screed because HF sounds are easily attenuated.

I think anything other than finding and fixing the leak(s) will be a
bodge. Problems will be huge if you find you have to start excavating
after occupation.

I think you're going to have to grasp nettle/bull by horns, identify
the leaking circuit(s) and start digging. :-(

On Fri, 16 Jun 2006 21:53:19 +0100, ChrisJ
wrote:

ChrisJ wrote:

Just been reading up and have found that fernox do a raditor leak fixer
for fixing inaccessible leaks. Would this work in the plastic UFH pipe?

Not if there is a nail or screw through it. Even if it works
temporarily the nail/screw will corrode quite quickly both making the
hole in the pipe bigger due to the expansion of the rust and
eventually corroding through leaving a hole too big for leak sealant
to work.

If ply was laid before tiles it is common to screw it down at about
12-24 in centres. I'd guess one or more (possibly all) of the screws
were too long and pierced the piping.

--
Peter Parry.
http://www.wpp.ltd.uk/

The message
from Peter Parry contains these words:

If ply was laid before tiles it is common to screw it down at about
12-24 in centres. I'd guess one or more (possibly all) of the screws
were too long and pierced the piping.

Seems odd to put ply down on top of UHF. Surely it'll insulate the floor.

--
Skipweasel
Pay no attention to that man behind the curtain.

On Sat, 17 Jun 2006 11:22:20 +0100, Guy King
wrote:


Seems odd to put ply down on top of UHF. Surely it'll insulate the floor.

It does a bit - but not significantly as it is a high mass/low
temperature system. It's no worse than carpet.

--
Peter Parry.
http://www.wpp.ltd.uk/

The message
from Peter Parry contains these words:


Seems odd to put ply down on top of UHF. Surely it'll insulate the floor.

It does a bit - but not significantly as it is a high mass/low
temperature system. It's no worse than carpet.

But he says "floor sheets, then ply then tiles". Why not just tile
straight onto the concrete?

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:
The message
from Peter Parry contains these words:



Seems odd to put ply down on top of UHF. Surely it'll insulate the floor.


It does a bit - but not significantly as it is a high mass/low
temperature system. It's no worse than carpet.


But he says "floor sheets, then ply then tiles". Why not just tile
straight onto the concrete?

The floor is suspended wooden floor on joists over an under floor void.
90mm Kingspan was suspended on battens between the joists with its top
30mm below the top of the joist, the pipes laid on the insulation and
the remaining gaps filled with screed to the level of the top of the
joists. Chipboard sheets are then laid followed by 3mm ply and then
tiles. Not sure why the 3mm ply was needed but I'm glad it was as it
means we can cut it out and start again without having to clean the old
tile cement off the floor sheets.

The solutions with blowing the rags trailing fine wire and applying
mains to them then using a wire detector sound great as did the using
compressed air. The former I think might not work due to the fact that
there is 50m of pipe in that half of the run with tight bends every 2 m.
I think the drag on the wire would mean the rag never got as far as it
should. Using a metal detector to detect the ball bearing I suspect
would fail due to the grid of screws holding down the ply at 8" centres.


Carpet is much more insulating than 3mm of ply. The ply is screwed to
the chipboard floor sheets (no concrete in this floor) with really small
screws that don't go through the chipboard sheets.

Action so far:

The manifold splits the floor into two loops of approx 5m pipe each. We
presurised the loops individually to find which half the leak was in.
Guessing the leak was going to be where the pipes crossed the joists
then I started at the door working along the wall and removed tiles, ply
and floorsheet until I found a wet patch, fortunatly after only having
removed about a dozen tiles.

Next job is to remove enough floor cover to replace the holed pipe with
a new section. Then get it retested to make sure there was just one
hole and then recover the floor.

The Underfloor heating company based in Sheffield came out next day
(Saturday) at no charge to help locate the leak and were really helpful
even supplying the compression fittings and a length of pipe to patch it
once I'd found it. I can't recommend them strongly enough but also I
don't think I'm allowed to mention them by name but try googling for
"under floor heating sheffield uk s8 9eh" if you want to find out more.

Thanks to all those who suggested ways of dinding the leak.

ChrisJ

ChrisJ wrote:
Guy King wrote:
The message
from Peter Parry contains these words:



Seems odd to put ply down on top of UHF. Surely it'll insulate the
floor.


It does a bit - but not significantly as it is a high mass/low
temperature system. It's no worse than carpet.


But he says "floor sheets, then ply then tiles". Why not just tile
straight onto the concrete?

The floor is suspended wooden floor on joists over an under floor void.
90mm Kingspan was suspended on battens between the joists with its top
30mm below the top of the joist, the pipes laid on the insulation and
the remaining gaps filled with screed to the level of the top of the
joists. Chipboard sheets are then laid followed by 3mm ply and then
tiles. Not sure why the 3mm ply was needed but I'm glad it was as it
means we can cut it out and start again without having to clean the old
tile cement off the floor sheets.

The solutions with blowing the rags trailing fine wire and applying
mains to them then using a wire detector sound great as did the using
compressed air. The former I think might not work due to the fact that
there is 50m of pipe in that half of the run with tight bends every 2 m.
I think the drag on the wire would mean the rag never got as far as it
should. Using a metal detector to detect the ball bearing I suspect
would fail due to the grid of screws holding down the ply at 8" centres.


Carpet is much more insulating than 3mm of ply. The ply is screwed to
the chipboard floor sheets (no concrete in this floor) with really small
screws that don't go through the chipboard sheets.

Action so far:

The manifold splits the floor into two loops of approx 5m pipe each. We
presurised the loops individually to find which half the leak was in.
Guessing the leak was going to be where the pipes crossed the joists
then I started at the door working along the wall and removed tiles, ply
and floorsheet until I found a wet patch, fortunatly after only having
removed about a dozen tiles.

Next job is to remove enough floor cover to replace the holed pipe with
a new section. Then get it retested to make sure there was just one
hole and then recover the floor.

The Underfloor heating company based in Sheffield came out next day
(Saturday) at no charge to help locate the leak and were really helpful
even supplying the compression fittings and a length of pipe to patch it
once I'd found it. I can't recommend them strongly enough but also I
don't think I'm allowed to mention them by name but try googling for
"under floor heating sheffield uk s8 9eh" if you want to find out more.

Thanks to all those who suggested ways of dinding the leak.

ChrisJ

Boy I am glad you found it.

Now for hindsight..what CAUSED it???

...I was so effin careful when I did mine about not routing it near where
screws were to go, not constricting it, and using little bits of slip on
corrugated tubing where it crossed screed boundaries..

Like most things that were very carefully planned and thought out
FIRST..its been faultless.

The message
from ChrisJ contains
these words:

I can't recommend them strongly enough but also I
don't think I'm allowed to mention them by name but try googling for
"under floor heating sheffield uk s8 9eh" if you want to find out more.

Don't see why not - good service deserves an airing.

--
Skipweasel
Pay no attention to that man behind the curtain.

On Sun, 18 Jun 2006 11:15:05 +0100, ChrisJ
wrote:

Action so far:

The manifold splits the floor into two loops of approx 5m pipe each. We
presurised the loops individually to find which half the leak was in.
Guessing the leak was going to be where the pipes crossed the joists
then I started at the door working along the wall and removed tiles, ply
and floorsheet until I found a wet patch, fortunatly after only having
removed about a dozen tiles.

Good stuff. What caused the leak?

cheers,
Pete.

On Fri, 16 Jun 2006 21:53:19 +0100, ChrisJ wrote:

ChrisJ wrote:

Pet @ www.gymratz.co.uk ;¬) wrote:

ChrisJ wrote:

and we discovered we have a leak somewhere under the floor which
wasn't there when the screed went down.



Myself, I'd be tempted to try some of that CH leak sealant liquid you
put in the system then allow to circulate.

It's sorted me out on one occasion.
I bet a screw has gone through a pipe!

Is pressure dropping rapidly of is it over the course of rays rather
than minutes?


My thoughts too. I hope the floorer and tile have good insurance or are
willing to redo it all for a four pack of beer!

The pressure drops within about 30 minutes. We've isolated the manifold
from the rest of the CH and the leak is definately there or under the
floor.

ChrisJ

Just been reading up and have found that fernox do a raditor leak fixer
for fixing inaccessible leaks. Would this work in the plastic UFH pipe?
Are these fixes generally permanent or is it a bodge that will need
repeated fernox applications? I'm presuming we have a screw through the
pipe or at least into it.

Its a presurised combi boiler. How would I get the fernox in?

See the SealedCH FAQ.
I'm concerned that the
1) The leak is too big. A 30 minute drop would be drip-drip-drip as you
read it out but not dribbling.
2) The leak sealer will only work where the water evaporates leaving the
sealer behind.

I'd be tempted to keep the pressure on it and try to see if you can find
out where the leak is. Perhaps by looking in through the air brick.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember ChrisJ
saying something
like:

I can't recommend them strongly enough but also I
don't think I'm allowed to mention them by name but try googling for
"under floor heating sheffield uk s8 9eh" if you want to find out more.

Why on earth not? This isn't Blue Peter with its daft blacked-out trade
names, you know.
--

Dave

Hi Chris. I know this is a while back, but do you remember how they actually found the leak?