tight sheathing

tight sheathing

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.