I've excavated a bit of concrete floor (where I'd reported dampness in
another thread), where the concrete had started to disintegrate under the
harder top layer.

There's CH pipe buried here, it was covered with blue and green stuff, that
had also permeated into the now powdery concrete. At places it was also wet!
Although there was no actual water gushing anywhere.

It this likely to be an actual leak of the pipe? Or could it just be
clamminess it's picking up from moisture already in the floor?

The coloured areas are either side of T-joint (where a pipe offshoot goes
across the hall to some mysterious destination, as as far as I know there
are no CH radiators or pipe work on that side of the house).

On another matter, how do you drain a Primatic CH system? I can't see any
relevant pipes going in or out of the hot water cylinder (which has
'Primatic' embossed on it).

(I was thinking of just replacing that bit of pipe, once I find where the
offshoot goes to. Or I might just replace the boiler and CH pipes anyway, as
they're pretty old. Using pipework above the concrete this time!)

--
Bartc

On 12/03/2012 14:19, BartC wrote:
I've excavated a bit of concrete floor (where I'd reported dampness in
another thread), where the concrete had started to disintegrate under the
harder top layer.

There's CH pipe buried here, it was covered with blue and green stuff, that
had also permeated into the now powdery concrete. At places it was also
wet!
Although there was no actual water gushing anywhere.

Does it look like this pipe was just laid in the concrete without any
sleeving or tape around it?

(concrete and unprotected copper don't always mix well!)

It this likely to be an actual leak of the pipe? Or could it just be
clamminess it's picking up from moisture already in the floor?

It could be the pipe is pin holed all over the place....

The coloured areas are either side of T-joint (where a pipe offshoot goes
across the hall to some mysterious destination, as as far as I know there
are no CH radiators or pipe work on that side of the house).

On another matter, how do you drain a Primatic CH system? I can't see any
relevant pipes going in or out of the hot water cylinder (which has
'Primatic' embossed on it).

Sorry, no idea.

(I was thinking of just replacing that bit of pipe, once I find where the
offshoot goes to. Or I might just replace the boiler and CH pipes
anyway, as they're pretty old. Using pipework above the concrete this
time!)

That or some variation seems like a good plan!


--
Cheers,

John.

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

John Rumm wrote:
On 12/03/2012 14:19, BartC wrote:
I've excavated a bit of concrete floor (where I'd reported dampness in
another thread), where the concrete had started to disintegrate under the
harder top layer.

There's CH pipe buried here, it was covered with blue and green stuff,
that
had also permeated into the now powdery concrete. At places it was also
wet!
Although there was no actual water gushing anywhere.

Does it look like this pipe was just laid in the concrete without any
sleeving or tape around it?

(concrete and unprotected copper don't always mix well!)

It this likely to be an actual leak of the pipe? Or could it just be
clamminess it's picking up from moisture already in the floor?

It could be the pipe is pin holed all over the place....

The coloured areas are either side of T-joint (where a pipe offshoot goes
across the hall to some mysterious destination, as as far as I know there
are no CH radiators or pipe work on that side of the house).

On another matter, how do you drain a Primatic CH system? I can't see any
relevant pipes going in or out of the hot water cylinder (which has
'Primatic' embossed on it).

Sorry, no idea.

(I was thinking of just replacing that bit of pipe, once I find where the
offshoot goes to. Or I might just replace the boiler and CH pipes
anyway, as they're pretty old. Using pipework above the concrete this
time!)

That or some variation seems like a good plan!



i'd replace with plastic *in* the concrete frankly - if its hot water
insulate it with a sleeve..



--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

"John Rumm" wrote in message
o.uk...
On 12/03/2012 14:19, BartC wrote:
I've excavated a bit of concrete floor (where I'd reported dampness in
another thread), where the concrete had started to disintegrate under the
harder top layer.

There's CH pipe buried here, it was covered with blue and green stuff,
that
had also permeated into the now powdery concrete. At places it was also
wet!
Although there was no actual water gushing anywhere.

Does it look like this pipe was just laid in the concrete without any
sleeving or tape around it?

Nothing that I could see. Unless it's now dissolved.

(At least I found where probably the true DPC is (a darker, harder layer two
inches below the surface with some gauze over it), so the thin paint-like
coating of bitumen(?) on the floor surface likely isn't it. Although oddly
the floor surface matches up with the DPC in the exterior walls.)

I'll have a closer look tomorrow. Also I might bleed a radiator, and see if
the water coming out leaves the same rust-tinted stains on the vinyl.

(concrete and unprotected copper don't always mix well!)

Didn't they already know this in 1968? And who decided that embedding pipes,
cables etc in concrete, making fault-finding and maintenance a nightmare,
would be a good idea?

--
Bartc

On Mar 12, 11:25*pm, "BartC" wrote:
"John Rumm" wrote in message

o.uk...

On 12/03/2012 14:19, BartC wrote:
I've excavated a bit of concrete floor (where I'd reported dampness in
another thread), where the concrete had started to disintegrate under the
harder top layer.

There's CH pipe buried here, it was covered with blue and green stuff,
that
had also permeated into the now powdery concrete. At places it was also
wet!
Although there was no actual water gushing anywhere.

Does it look like this pipe was just laid in the concrete without any
sleeving or tape around it?

Nothing that I could see. Unless it's now dissolved.

(At least I found where probably the true DPC is (a darker, harder layer two
inches below the surface with some gauze over it), so the thin paint-like
coating of bitumen(?) on the floor surface likely isn't it. Although oddly
the floor surface matches up with the DPC in the exterior walls.)

I'll have *a closer look tomorrow. Also I might bleed a radiator, and see if
the water coming out leaves the same rust-tinted stains on the vinyl.

(concrete and unprotected copper don't always mix well!)

Didn't they already know this in 1968? And who decided that embedding pipes,
cables etc in concrete, making fault-finding and maintenance a nightmare,
would be a good idea?

--
Bartc

Burying pipes in concrete was common practice. The copper then was
thicker guage. (You will probably find it is imperial dimensions.)
Usually it was just taped up but cowboys didn't bother.

Best thing is to cut it off and abandon it. Replace with above ground
pipe.

To check what it feeds, you can buy cheap metal detectors.

You can get plastic skirting that has channels to put pipe in looks a
lot neater.