Furring
From BiblePortal Wikipedia
Furring [1]
(1): ( v. t.) Double planking of a ship's side.
(2): ( v. t.) The strips thus laid on.
(3): ( n.) The leveling of a surface, or the preparing of an air space, by means of strips of board or of larger pieces. See Fur, v. t., 3.
(4): ( v. t.) A deposit from water, as on the inside of a boiler; also, the operation of cleaning away this deposit.
(5): ( p. pr. & vb. n.) of Fur