EWF-11Fix the skirting or beading, then clean upCables and pipes can run behind any wall too, so keep using the detector and still treat the wall as live until you've drilled a small test hole and checked what's coming out; isolate the circuit at the consumer unit first if you're at all unsure. Fix solid brick or block with a 6mm drilled hole, a matching plug and a 40mm screw; drive a 40mm woodscrew straight into the centre of a timber stud with no plug needed; on a metal stud, never use a wood screw or a plain plastic plug, as it strips straight through 0.5mm steel — use a self-drilling metal-stud fixing instead. Where a fixing lands on bare plasterboard between studs, use a lightweight toggle fixing, and on lath and plaster walls, drill a fine pilot hole first and aim for a lath or noggin, or use a plasterboard-rated fixing so you don't crack the old plaster. Refit numbered skirting lengths with screws every 400-500mm, or pin scotia beading into the skirting board itself — not the wall — over the expansion gap, mitring corners at 45°.