We live in an Edwardian semi perched on the side of a hill with a balcony/terrace off the back from the kitchen. There are then steps down to the garden. Under the terrace is a storage area which I think was originally used as a cold store (heavy marble stone floor). Problem being water ingress from the paved balcony into the storage area below which is causing damage to the entire structure. I had local builders re- pave the terrace and paint waterproof coating beneath the slabs but it's got worse since then if anything. There is a small sloping roof above which keeps half of it dry and the surface itself is sloped away with a small wall on one side. Does anyone have a similar set up and managed to maintain a dry area underneath? I'd speak to my neighbours but they have all extended out so have a kitchen over the storage area with a flat roof.