Damp - should we lift a concrete floor

Our stone cottage is damp - we knew that before we moved in about a month ago. We've had some very good advice about reducing the causes - namely external ground levels, poor roof/gutters, lack of ventilation, bad rendering.

But in the dining room the previous owners have applied a hard plaster to the wall (a form of tanking I believe) and put down a concrete floor. The hard plaster goes just over a metre up the walls and is blown in a few places and damp has risen above it and affected the old plaster higher up the wall.

The floor was covered with a sheet of polythene, then some insulating sheeting and then a clip together wooden floor. The concrete under the polythene was very wet, which leads me to guess that there's no DPM installed.

The traditional answer is to hack off all the affected plaster and replace it with a Lime-based plaster and breathable paint (lime wash). Also to lift the concrete floor, and use flagstones on to a lime- mortar base, thus creating a breathable floor.

I've asked about chemical dpm's and though they'll happily sell me one, other people say this wont work with out stone/rubble walls.

But whilst I can lift the floor (I think), hacking the tanking plaster off the wall is nigh on impossible - I've been using a cold chisel and lump hammer but it's as if it's become one with the stone behind.

If the concrete floor has been laid with a DPM, then isn't it breathable already - couldn't I just mortar a thin stone floor over the top, without polythene and create the same breathable effect?

Is there a better way to get the tanking off the wall and replace with a lime-based plaster?

Simon

Reply to
Bitstreams
Loading thread data ...

Why not tank it all the way to the roof?

And forget this stupid 'lime plaster is the cure for dampness' bullshit.

Reply to
The Natural Philosopher

Just a suggestion, but I would investigate wether or not their is a river running under your property before you carryout any remedial work.

Reply to
the_constructor

How? By digging it up?

Reply to
Mogga

This is the last place to ask such a question. Ask folk that understand the subject

formatting link

Reply to
meow2222

Why is the ground under the concrete quite so wet?

Is it possible you're looking at the residual effects of the polythene/ laminate floor having acted as a moisture trap for some time?

If you want to take off the tanking plaster, I'd have thought an sds chisel would make life a lot easier than hand chiselling.

If you do take the tanking plaster off, you still have the moisture problem whether it rises above it or not.

Are you sure it's all rising damp?

If you have thick rubble walls, it may just be that lots of patience (& warmth & ventilation) is all that's required to slowly reduce the moisture levels.

Reply to
dom

You understand it, and you're here, so why don't you answer?

Reply to
Stuart Noble

Nothing on that site is anything but dimly understoood prejudice.

Reply to
The Natural Philosopher

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.