Coverage A 27.2kg (60lb) bag will cover approximately 1.2 m2 (12 sqft) at 12mm (1/2") thickness. Coverage in joints will vary with width. Directions Add 3.7L (1 gallon) of water into the mixer for each 27.2kg (60lb) bag. Mix mortar thoroughly for a minimum of 5 minutes. Adjust water as needed. Use only clean potable water. Prepare surfaces properly. Consult stone veneer manufacturer's instructions. Apply ½" of mortar over CMU wall, sheathing or rigid insulation. Apply ¾" of mortar to the back of each stone unit. Cover back completely. Press coated unit firmly on wall. Some mortar should be squeezed out around the stones edge. Ensure complete coverage between vertical surface and back surface of the stone. Use a grout bag to fill in joints. Avoid smearing on stone. Accidental smears should be removed only when dry. Use a dry brush. Finish joints when thumbprint dry with a metal or brush tool.