I've just come across a few useful threads on here about french drains and I'm hoping to get some advice on how to go about creating one.
We recently moved into a late 19th century ground floor garden flat in a terrace in north London. Our pre purchase survey indicated that we had damp throughout the rear of the property and I suspect this is caused by the concrete slab that forms our garden and a lack of drainage. As you can see on the photographs, the garden level has been raised to the air brick and the interior level is now lower than the exterior. There is also cement...