Fwom:Roger )
The message from "Mike"
contains these words:

B. Apply expanded clay in lime plaster to the interior. This
gives
insulation with no vapour barrier, retaining wall
breathability, and
without the damage cement sometimes causes.

Not a solution I have previously heard of. How effective is that
plaster
mix as insulation?

I use it for floors as it needs to be a lot thicker than
Kingspan/Celotex or
even Rockwool. LECA (Optiroc) in a lime/sand mix to a foot or so
depth
definitely does lower heat loss through the floor though. A friend
did put
a thin layer of it as an outside render but this was on a 'best
attempt'
basis rather than trying to meet part L.

I had a google but couldn't find any reference to its use as wall
insulation. One of my round tuits near the top of the pile is to dig
up
and re lay my solid ground floor but I think I will avoid the
expanded
clay route as I would probably have to dig out to below my shallow
foundations. I can't afford to raise the floor level at all as
headroom
is aleady minimal.


One option might be to dig to full depth over most of the floor, but
dig progresievly shallower at the edges, so the cone shape of soil
under the walls is not disturbed. Then you get agood load of
insulatino in without destabilising the walls.

Understand I'm only talking generalities here, not advising you to do
anything.


I am in a similar position to the op other than I have 2' thick
rubble
filled stone walls and no external render.
Same here.

I note you have gone the batten out route but I have small rooms and
particularly in the kitchen, smallest bedroom and bathroom no space
for
more than the thinest of insulation. One of my earlier jobs (still
not
plastered out because of the insulation dilemma) was to increase the
size of the bedroom at the expense of the bathroom so space is really
tight in there now.

1" of insulation makes a big difference. Cavity wall insulation is
only normally 2", and 1" has over half the effect of 2".


NT