Hello. I have the foundations of an old outhouse taking up approximately half of the rear wall of my house. The other half consists of shoddy crazy paving. There is a slope away from the house on the crazy paving, but the outhouse foundation is level. I want to kango off the outside edges of the outhouse to gain a slope for water run off, and then cover the whole lot with gravel right up to the house wall. The gravel would be below the damp course, but resting against the concrete foundation level of the house. Is there any damp issues with doing this? My husband says there could be, but I think that if the gravel is below the damp course it should be fine. Or do I need to leave an air gap?