For most applications, metal lath attachment over concrete block/concrete has always been the preferred method regardless of the condition of the block/concrete. This is because the lath provides a redundant measure that ensures the integrity of the attachment of the stucco to the block/concrete and also gauges the final thickness of the application. This is important considering the thermal changes of the environment. Like in direct applications, it is recommended that all of the masonry joints be flush and not struck. 3.4 lb. self furred galvanized lath is then attached to the masonry/concrete with corrosion resistant powder actuated fasteners in accordance with ASTM Standard C 1063. In this system the scratch coat is applied +-1/2" thick, followed by a brown coat of +-1/4" minimum thickness and a +-1/8" cementitious finish coat. If an acrylic finish is substituted in lieu of cementitious, the combined thickness of the scratch and brown coats should equal +-7/8".