Split-faced units can also be manufactured with ribs or scores to provide strong vertical lines in the finished wall. Rough textures, like those available with split face units, are often used in areas prone to graffiti, as the texture tends to discourage graffiti vandals.
Split face units are governed by ASTM C 90, which includes an allowance to account for the rough face. ASTM C 90 prescribes minimum faceshell thickness requirements for all load-bearing concrete masonry units, but also contains a variance for split face units where up to 10% of a split faceshell can be less than the minimum specified thickness, but not less than 3/4 in. (19 mm). This 10% limit does not apply, however, when the units are solidly grouted.