On Tue, 02 Nov 2004 20:12:14 +0000, tez wrote:

Thank you all for your advice. I have dropped the idea of putting
levelling compound and tiles over the stone floor.

If I go with levelling the sandstone slabs - would it be better to let
the floor breathe rather than put an impermeable layer beneathe the
stones. One wall is going to be tanked to a certain height as it is a
earth retaining wall on a slope, and I cant remove that earth as the
house above is sitting on it! The other 3 walls have old lime plaster
which has been thinly skimmed to make them level.

What do you think of this approach - raising the slabs, clear the
concrete bits, lay lime mortar on the earth, relay the good slabs on
the lime mortar (?) to level the ground and let it breate and fill
in the space left with new slabs. Would I seal the stones to stop them
staining and let the stones breathe through the mortar or not seal
them at all?

A surveyor suggested digging down a bit and laying the the stone slabs
on concrete pods. Has anyone had experience of this? I think it is
with the intention of having an airspace below the floor.

Should I install air bricks on the wall which leads down to the cellar
(below the kitchen floor level) which would allow the ground to
breate into the cellar (beneath the lounge and hall) and put a couple
of air bricks at the end of the cellar which would allow air to
exchange with outside air, or put airbricks on an external kitchen
wall above the kitchen floor which would allow moisture to escape once
it has come up through the floor?

THank you for your help

Hi,

How about laying the sandstone slabs on... sand? Also try taping a 4'
square sheet of plastic to the walls and floor, that will give some
idea of how much damp comes through over time.

If you put an impermeable layer down the risk is that water will build
up behind it and seep out round the edges in an unsightly way, having
less opportunity to dry out naturally.

It might be that the earth retaining wall doesn't really need tanking,
whether the house is on well drained or impervious soil will make a
huge difference.

A stone flooring specialist will be able to advise on a foundation and
sealer for sandstone, lithofin stainstop has been recommmended on here
IIRC. It won't make the sandstone vapour proof, just stop liquids
soaking in.

The best way for damp to escape is through the fabric of the rest of
the building, so ensure the walls are painted or papered with
something breathable. Airbricks that can allow damp air into a cold
place won't be much good, but a kitchen extractor or cooker hood can
help keep steam from building up when cooking.

cheers,
Pete.