"BigWallop" wrote in message
...

"Clive Summerfield" wrote in message
...

"BigWallop" wrote in message
...

"Grunff" wrote in message
...
BigWallop wrote:

But the water present in the plaster is present as adsorbed
water. Very little will be present as gaseous water in the small
air voids in the plaster. So how is this adsorbed water, already
a liquid, going to condense out onto the pipe?

--
Grunff



Warm moist air. Cold water pipe in wall. Do the math.

Did you actually understand any of the above explanation? I
strongly suspect not.

--
Grunff


If you have a cold spot on or in the wall, from any kind of source and
at
any depth, it will cause moisture from the air to condense on that
part
of
the wall. For hundreds of years internal pipes have been placed in
boxed
pipe chases. I wonder why they have done it way for so many years ?
OK,
maybe your right and everyone else is wrong.


No, in this case you're correct (and agreeing with grunff) that the
condensation will form on the wall. But your original reply stated...

"If you do want to bury the pipe, then make sure it is lagged and is
inside
a
boxed chase. This stops any condensation which forms on the ***surface
of
the
pipe*** from damaging or causing damp marks on any plaster work that is
around
it."

Note the added emphasis. The condensation may form on the surface of the
wall where the plaster overlays the pipe, but it is extremely unlikely
to
form on the surface of the pipe itself.

Cheers
Clive



Yes that was my original reply, because, if the pipe is in a boxed chase
it
is not directly in the plaster so condensation can and will form on the
surface of the pipe, therefore, it needs to be lagged to stop this
happening. Read till you understand, not till you make your mind up.


Yup, point taken. It was the "if you want to bury the pipe" that threw me,
as I'd never considered chasing out to bury the boxing, usually box in on
surface or simply bury it.

Cheers
Clive