1468.04  LATH, PLASTER AND DRYWALL.
   (a)   Grounds.  Where lath and plaster are used, all grounds for doors, windows and other openings must be not less than three-fourths inch by three-fourths inch.  Base grounds must be not less than three-fourths inch by two inches.
   (b)   Cornerites and Beads.  All corners and ceiling angles shall have cornerites, and all outside corners and arches shall have corner-beads nailed into solid framing.
   (c)   Lath.  Where lath and plaster are used, the minimum thickness for gypsum lath shall be three-eighths inch for studs or ceiling joists sixteen inches o.c. and one-half inch for studs or ceiling joists twenty-three inches o.c.  Where metal lath is used, it must be installed according to A.I.A. standards.
   (d)   Nails.  Nails for lathing must be thirteen gauge, one and one-eighth inch blue nails with nineteen-sixty fourths inch flat heads for three-eighths inch lath and a similar nail one-eighth inch longer for one-half inch lath.
   Gypsum lath, sixteen inches wide, shall be secured by four nails per lath in each support and five nails for twenty-four inches o.c.  The same schedule applies when using No. 16 U.S. gauge galvanized wire staples with seven-sixteenth inch wide crown and seven-eighths inch legs.
   (e)   Plaster.  Plaster must consist of two coats, brown and finish, for gypsum lath and three coats, scratch, brown and finish, for metal lath.
   (f)   Drywall.  Drywall must have a minimum three-quarter hour fire rating.  A minimum of one-half inch shall be used on studs or ceiling joists sixteen inches o.c. and five-eighths inch on studs or ceiling joists twenty-four inches o.c.  When paneling is used, a three-quarter hour fire rating must be achieved before paneling is applied. 
(Ord. 42-1981.  Passed 2-23-81.)