PB-04Check for cables and pipes before you drillCeiling voids often carry cables for lights and sometimes pipework for a bathroom above, and cables can run almost anywhere, not just in neat lines. Use a detector, but still assume something could be there — detectors miss cables that are deep, in metal conduit, behind metal-backed board, or a metal joist frame can confuse a cheap detector further. If you have any doubt, isolate the relevant circuit at the consumer unit before drilling. Find your stopcock now (usually under the kitchen sink) and check it turns, so you can shut the water off fast if you hit a pipe.