Water under walls - Water entering house under the wall

[IanW]

Our French (Brittany) house has 0.75m thick granite/flint walls, and is built into the garden so the back of the house is 0.75 meters under the ground level - a gradual slope from the front to the back of the house on one side of the house only. 2 years ago, in really heavy rain, clear water came in at floor level at the thinnest point of the side wall - the fireplace. Discovered the roof gully down pipes fed straight into the ground at the side of the house. Solution - dig out side of house, deflect downpipes to a soakaway 5 meters away, render side of house with additive to ground surface level, line with heavy duty plastic curving outwards at bottom from the house and refill hole (now flower bed). Replaster fireplace with water proof additives included. No problems for 2 years, but after heavy rain - very heavy rain a few days ago after a dry summer - again about 1 pint of water came in at the same point. It is a tiled floor, so no problems with damage, but how can we resolve without the great expense of permanantly digging away the land (to make a patio or something). As the house is so old, there are no foundations as such, and our builder thinks heavy rain at a certain angle could have got down between the plastic and the wall (the plastic protudes about 3 inches above the ground) and under the wall again. Reckons solution is to solidly seal between the plastic and the wall. Any thoughts or comments from anyone? Thanks!

[Tony McC]

Sounds a bit complicated to me - I reckon you'll need whatever is the French equivalent of a building surveyor - Un Surveyeur de maisons - to have a good look at what's happening and suggest the most suitable remedy.