Could I please have some electrical advice and opinions? In the past , prior to Part P,I have done quite a lot of wiring. I believe I am cautious, and want to comply with regulations. I am currently doing some of the ‘spadework’ (literally) to provide a large shed with a mains elctricity supply. In due course a qualified electrician will inspect, do whatever parts of the work he wishes and certify. I can’t contact him at present, but he advised me that if I ran the cable underground, it should be at least 500mm below the ground, and where digging is possible it should be 600mm. If the electrician was accessible now I would say to him that much of the underground run is below a large layer of concrete, so is there a provision to go less deep, when the cable is covered by concrete? I have broken a channel a spade’s width in the concrete, and will relace it with concrete when the job is done. The concrete is about 3 inch thick. Is what my electrician told me guidance or regulation? Must I really dig 500mm down? It is very tiring! Thanks for any help