Wet rock wall from rain

[osie]

Hi All

I have a rock wall that due to lots of rain lately has flooded the room it is in.  The rain has now subdued and so it is not such a problem any more. 

The wall has been half hidden by a plaster wall supported by metal which then turns into a shelf fully covering half the lower wall.  I checked behind the wall(by making a hole in it) and it is quite damp back there... Also there is a gutter allowing the water to flow behind the plaster wall, but this may have filled up and therefore leaked into the room.

My question is... what do you do with a wall that  is pourous and leaks into the room.

The plaster wall is okay but not great.  On the other hand it is better than having a little waterfall in the room.

any ideas  much appreciated.

Thanks in advance

osie

[AnOther]

I'm no expert but I suspect that apart from trying to direct water away from the affected wall there may not be much you can do to prevent this.

Stone walls need to breath and bereft of a damp proof course, as so many older French properties are, any attempts to make them impervious to rain could potentially make  the problems worse by trapping damp inside.

 

[WJT]

We had a similar situation and had a special membrane put on the back stone wall that allowed it to breath but stops the water penetrating. A small drain put in the floor for the water to dissipate and then a tanking wall that was built about 10 cm in front of the back stone wall made of thin red brick, then plastered over. There are ventilation grills in the tanking wall, one at the bottom of the wall and one at the top opposite side for ventilation.

It has been a little over a year and (unfortunately [:(]) lots and lots of rainfall to test it. So far it has worked and no sign of damp.

[AnOther]

No wonder the French prefer new builds [:-))]