(a) If you use loose-fill surfacing materials in your outdoor active play space, you must install and maintain nine inches or more of uncompressed loose-fill material in the use zones.(b) You must not install loose-fill surfacing materials over concrete or asphalt.(c) You must mark all equipment support posts to indicate the depth at which the loose-fill surfacing material must be maintained under and around the equipment.(d) You must ensure the loose-fill materials are maintained at the proper depth at all times.(e) Loose-fill surfacing materials must not be used indoors.