"Martin Bonner" wrote in message
...
On Mar 13, 12:45 pm, "Tony" wrote:
"Martin Bonner" wrote in message

...


I concur with Mary's response: Who told you that? If it was "a mate
in the pub", ignore them; if it was a building surveyor (or architect)
who has experience with buildings of similar construction, then they
probably know what they are talking about (but I am surprised).

At first it was a builder friend who, whilst discussing a damp patch which
was high up on a bedroom wall, explained that it was likely to be debris
bridging the cavity and allowing water to cross. He added thats a reason why
cavity wall insulation can cause damp problems.
Since then I have heard that more modern fill materials do not cause the
same problems, but when I contacted a firm with a view to getting the cavity
filled, they were not interested because of the age/construction of the
house.


Also, in the kitchen I have a solid floor, stone flags, bedded
presumably
on hardcore/cinders or similar. I intend putting a water based underflor
heating system under the flags and having an exposed stone floor. Part of
the reason I am looking at insulation in the room is to help with the
warm-up time which I think will be longer with UFH than with the radiator
I
currently have,(which SWMBO wants taking out to get furniture and units
on
all walls).

Well with UFH under stone flags, I would expect a warm-up time so long
that you will (effectively) have to have it on all the time - in which
case insulation won't matter (apart from the small matter of the
staggering bills).
Looking on the website of an UFH supplier, stone is apparently an excellent
medium for heat transfer, about the same as the screed over the pipes. They
recomend 60 to 100mm of thickness above the pipe and I would guess the
flags are 50 to 75mm thick.
I have to lift the flags for levelling, so while they are up I can dig out
150mm or so, to lay hardcore, insulation, UFH pipes and screed, before
re-laying the flags on what will have to be a continuous layer of cement
rather than spotting, to avoid cold areas.
I have thought about the warm-up time and might have to use a night
set-back control to drop the temperature a few degrees without cooling down
completely.
Cheers,
Tony.