DF-03Run a proper relative humidity (RH) testBefore drilling, check the floor with a cable and pipe detector, then still treat it as if something's there. Solid floors often hide underfloor heating pipes or electric cables chased into the screed, and detectors can miss anything deep or shielded. Find your stopcock, usually under the kitchen sink, and check it turns freely before you start so you can cut the water off fast if you hit a pipe; if you're at all unsure, isolate the relevant circuit at the consumer unit first. Drill a 25mm hole about 40mm deep in two or three spots away from walls, insert the hygrometer probes, seal them, and leave for at least 72 hours before reading the result against your flooring manufacturer's stated limit.