As my screen name suggests I am pretty new to all this so please excuse the daft questions. I have today managed to prise 15 paving slabs from around a paved area in my back garden.( am currently very tired and stiff). I was wondering if anybody coult tell me how deep I need to dig out for a new border. The reason I ask this is because I have managed to remove approx 8 inches of solid clay and below this level appears to be a bottomless amount of builders rubble( mostly large blocks of cement and breeze blocks. I am intending to remove all the clay from the entire bed and refill with topsoil. Thankyou in advance for your help.
Jane