Our CH is in the utility room of our bungalow. Because the corridor
outside is a solid, concrete one, the CH fitter took pipes across the
loft, and dropped them down the wall where they disappear into the
floor, and emerge the other side, into the floor void of the front
room. From there they go round the rest of the house which has
floorboards and voids. Presumable a little drilling was needed for
this solution, rather than trying to cut channels in the concrete.

Anyway, I have just noticed a green powder on one of the pipes, where
it emerges/disappears into the concrete.

Can't see any pressure loss in the system, but this is clearly an
early leak ?

All pipes were replaced 8 years ago (I saw it with my own eyes) so
these are (to me) fairly new pipes.

How far from the stain is the leak likely to be ? Can it be *below*
the stain, and capillary action has caused the liquid to draw up ? Or
is the leak likely to be exactly where the stain is ?

Best solution to cut the pipe out, and replace ?

On 1 Nov, 17:13, Jethro wrote:
Our CH is in the utility room of our bungalow. Because the corridor
outside is a solid, concrete one, the CH fitter took pipes across the
loft, and dropped them down the wall where they disappear into the
floor, and emerge the other side, into the floor void of the front
room. From there they go round the rest of the house which has
floorboards and voids. Presumable a little drilling was needed for
this solution, rather than trying to cut channels in the concrete.

Anyway, I have just noticed a green powder on one of the pipes, where
it emerges/disappears into the concrete.

Can't see any pressure loss in the system, but this is clearly an
early leak ?

condensation from summer non-use? clean pipe and paint it see what
happens?

Jim K

On Mon, 1 Nov 2010 10:19:21 -0700 (PDT), Jim K wrote:

condensation from summer non-use? clean pipe and paint it see what
happens?

Or veridgres from acid flux not cleaned off properly. Nearly all the
soldered joints in this place are green, apart from the ones I've
done and wiped the flux off afterwards...

--
Cheers
Dave.

On 1 Nov, 17:47, "Dave Liquorice"
wrote:
On Mon, 1 Nov 2010 10:19:21 -0700 (PDT), Jim K wrote:
condensation from summer non-use? clean pipe and paint it see what
happens?

Or veridgres from acid flux not cleaned off properly. Nearly all the
soldered joints in this place are green,

bloody plummers, may as well get the scouts in..

Jim K

Jethro wrote:
Our CH is in the utility room of our bungalow. Because the corridor
outside is a solid, concrete one, the CH fitter took pipes across the
loft, and dropped them down the wall where they disappear into the
floor, and emerge the other side, into the floor void of the front
room. From there they go round the rest of the house which has
floorboards and voids. Presumable a little drilling was needed for
this solution, rather than trying to cut channels in the concrete.

Anyway, I have just noticed a green powder on one of the pipes, where
it emerges/disappears into the concrete.

Can't see any pressure loss in the system, but this is clearly an
early leak ?

All pipes were replaced 8 years ago (I saw it with my own eyes) so
these are (to me) fairly new pipes.

How far from the stain is the leak likely to be ? Can it be *below*
the stain, and capillary action has caused the liquid to draw up ? Or
is the leak likely to be exactly where the stain is ?

Best solution to cut the pipe out, and replace ?


Copper pipes are meant to be sleeved if they go through anything with cement
in it as the cement attacks the copper.
Plumbers normally wrap pvc tape around the pipes, but they often don't.

Of all the copper pipes I have removed in these situations, the only visible
damage to the pipes are where they emerge from the concrete - that is to
say, the pipes are normally unblemished where they have been completely
encapsulated in cocrete, but where the concrete stops is where the verdigris
and usually severe rot is.

If it were mine I would remove about 6-8 inches of the concrete along the
pipe's length, cut out and replace about 6 inches in each direction (both
above and below ground) and wrap this new piece in insulation tape before
re-concreting.
--
Phil L
RSRL Tipster Of The Year 2008

On 1 Nov, 17:13, Jethro wrote:
Our CH is in the utility room of our bungalow. Because the corridor
outside is a solid, concrete one, the CH fitter took pipes across the
loft, and dropped them down the wall where they disappear into the
floor, and emerge the other side, into the floor void of the front
room. From there they go round the rest of the house which has
floorboards and voids. Presumable a little drilling was needed for
this solution, rather than trying to cut channels in the concrete.

Anyway, I have just noticed a green powder on one of the pipes, where
it emerges/disappears into the concrete.

Can't see any pressure loss in the system, but this is clearly an
early leak ?

All pipes were replaced 8 years ago (I saw it with my own eyes) so
these are (to me) fairly new pipes.

How far from the stain is the leak likely to be ? Can it be *below*
the stain, and capillary action has caused the liquid to draw up ? Or
is the leak likely to be exactly where the stain is ?

Best solution to cut the pipe out, and replace ?

Concrete being alkaline it does not attack copper or steel but in fact
preserves them. However if there is an expansion/heating issue the
the pipe needs to be coated to allow it to expand. If it hasn't been
so coated then something has to give, usually the pipe.
However it may just be condensation. Keep and eye on it, if it's a
leak it will eventually manifest itself.