EWF-01Check the subfloor and fix loose boardsWalk the whole floor and listen for squeaks or movement. Screw down any loose or bouncy boards into the joist below with a countersunk screw, rather than just nailing. Before you drive any screw into the subfloor, know that cables and pipes can run almost anywhere underneath it, especially near skirting and under sockets. Use a cable and pipe detector, but still treat every spot as if something is there until you prove otherwise — detectors miss cables in metal conduit or lying deep. Find your stopcock (usually under the kitchen sink) and check it turns before you start, and if you have any doubt, isolate the electrics at the consumer unit before drilling.