French Ditch Method For Preventing Damp

MrHappyChap

Has anyone heard of the French ditch method for preventing rising damp, and how effective it is? Here's a description of it...

"Dig a deep ditch around and then away from the building. Dig it as deep as you can without endangering the building. Then lay in a large vented drain pipe, and cover it with large clean stones to within 6" off the ground surface. Then lay a slate cover, like a roof, draining away from the footings, and turf over it. In this way any water in
the ground will drain away leaving the cottage standing upon a dry island. Any water running down the wall will be drawn away from the footings and will enter the rubble fill and drain into the ditch. This technique is called a French ditch. When used properly, it cannot fail."

From the description, I would imagine this would not be effective in a mid-terraced stone house which fronts directly onto a public footpath i.e. so not easy to dig up at front of house, and not possible to dig up at sides of the house.