Hi all , I am currently trying to convert our front bedroom into a bathroom upstairs. It’s a semi detached property with side path to the back of the property which is where the first man hole is , this leads to the second man hole at the entrance of the property. Based on the location of the 2 man holes I can tell the clay soil pipe is going under the side path. The distance between the 2 manholes is around 25 meters. Is there an easy way to know how deep the clay pipe is before digging ?