WP-03Check for cables and pipes before drillingCables and pipes can run almost anywhere behind a wall, not just in the usual safe zones, so run a detector over your marks first. Even so, treat the wall as if something is there until you prove otherwise — cheap detectors miss deep cables, cables in metal conduit, and anything behind metal-backed plasterboard. Find your stopcock now, usually under the kitchen sink, and check it turns, so you can shut water off fast if you hit a pipe. If you have any doubt at all, isolate the relevant circuit at the consumer unit before drilling.