Rib lath has eighteen ribs approximately 1/8 inch high, spaced 1½ inches on center to provide additional rigidity for horizontal stucco applications. There are approximately 8,500 openings or keys per square yard to aid in keying. 2.75 lb. and 3.4lb. may be used for horizontal spans up to 16” o.c. and 19” o.c. This product is also used extensively as a base for ceramic tile.