On some coal faces, the stone overlying the seam does not always fall in the wastes after withdrawing the supports. To avoid excessive weight on the face, which would cause dangerous roof conditions, it is desirable to blast down the stone in the wastes. Also, in thick seams, the overlying strata requires breaking down to provide sufficient stone for building packs. The holes for waste shots must be drilled from the face side so that the driller is working under a supported roof. Care must be taken to ensure that the holes are not drilled up into the solid strata and that the burden on the shot is not excessive.