I have to have the copings on my stone gable end taken off and rebedded, as they let water in. A bloke down the road had it done and I saw that they went to some trouble to put lead soakers underneath (cemented over in pic), but I didn't take much notice at the time. Picture of the finished job and my diagram of supposed construction attached. I would like to be sure that whoever does it, does it OK, but searching online so far has not shown me what OK is! Varying opinions on a lead cover under the coping, etc. Any ideas here?