For some reason, there is an exposed pipe in my kitchen that feeds
the cold water supply to the tank. Is it feasible to reroute this by
burying it in the plaster of the wall and if so, does it need to be
insulated (and if so - with what)? Or, as it is only an inch or two
from the wall in a corner, would it be better to just box it in?
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
Interesting reasoning. How exactly do you expect condensation to
form on a pipe that is burried in plaster?
In order for condenstation to form, the pipe has to be in
contact with air carrying some water vapour. Being in contact
with plaster which is at equilibrium with the air *will not*
result in condensation on the pipe's surface.
I have threaded 15mm pipe up 20mm plastic electrical conduit
and used that in a chase. A small obtuse bend (22mm pipe bender
works OK on this combination) is used to bring the pipe out of
the surface of the wall. Also made sure there was some freedom
of movement between the pipe and conduit. I wouldn't want to do
a long length because of the differential expansion. Don't do
any joins in the wall.
Water vapour (and air) will migrate through plaster, and will
form wet areas in cold spots.
I'm sorry - that just doesn't make sense.
The plaster will indeed have a certain moisture content (as all
materials do), which will be in equilibrium with the air. No
The assertion that this water will condense out on the pipe is
what I have a problem with. Condensation is a phase-change
phenomenon, where a large volume of gaseous water condenses on a
cold surface to produce a small volume of liquid water.
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?
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
boxed chase. This stops any condensation which forms on the ***surface of
pipe*** from damaging or causing damp marks on any plaster work that is
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.
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.
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