If you mention the Handbook in your documents, note that the new Handbook, the tolerance for ceilings has increased from 1/4" in 12 ft. to 1/4" in 10 ft. This puts it into agreement with ASTM C636.
If you mention the Handbook in your documents, note that the new Handbook, the tolerance for ceilings has increased from 1/4" in 12 ft. to 1/4" in 10 ft. This puts it into agreement with ASTM C636.