1. Tongue-and-grooved boards or dressed-and-matched boards nailed to rafters or studs to serve as a base for an outer covering; may be fastened either at right angles or diagonal to the supports.
2. Same as closed sheeting except that the vertical sheathing planks are interlocked; used in saturated soils; sometimes steel sheet piling is used instead of wood planking.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.