GW-04Check for cables and pipes before you drillCables and pipes can run almost anywhere in a wall, not just in the usual safe zones, so run a detector over every mark first. Even then, treat every hole as if something could be there — detectors miss cables that are deep, in metal conduit, or behind metal-backed plasterboard. Find your stopcock now, usually under the kitchen sink, and check it turns freely, so you can shut off the water fast if you ever hit a pipe. If you have any doubt at all, isolate the relevant circuit at the consumer unit before drilling, and turn off the water at the stopcock before drilling anywhere near a bathroom or kitchen wall.