Metal detectors are bound by no restrictions. They can and do operate in almost any type of environment that can be imagined. Targets thought to be located within walls, beneath floors or behind bricks in the hearth can be located with a metal detector. There are some cautions of which one should be aware to improve the chances of success. Nails, piping and wires will be quite commonly found. Should these be eliminated from detection some very good and hard sought targets may be overlooked. The more one knows of his equipment and how it operates and how to operate it for maximum efficiency the greater the opportunities for success.
Be as sure as possible of your target. Just because you get a target signal in the floor, be sure that it is not re-bar in the concrete. Numerous beeps or chatter may not be treasure but may be electronic interference caused by the motors of appliances, transmission signals for televisions, radios and telephones. It may be advantageous to reduce to detectors depth/sensitivity setting until the detector is more under control. Lastly, don’t destroy a wall just because a target has been indicated. One person we know did that and had found only a metal picture frame on the backside of the wall searched. It takes just a moment to check.