Get someone to help you lift the bath into the cradle. Then make sure it rests on the frame and sits snugly in the mortar bed. Now fill the bath with something heavy to weigh it down. In this case, because our bath isn't plumbed, we've used bags of brickies sand. Once the bath is firmly in place, finish the job by using your hands to mould the mortar around the base of the bath and leave it to set for 24 hours.