It is hereby declared unlawful for any registrant to raze or demolish any building or structure in such a manner that there shall remain holes or depressions dangerous to life or limb. The registrant shall remove from the site all wood, metal, and foundation and footing materials subject to decomposition. Concrete, bricks, and concrete blocks may be used as fill material for holes or depressions; provided, the materials are entirely covered by fill sand or earth which is then compacted. Holes must be made in concrete floors to permit passage of water.