Is there any standard for tolerances in masonry construction? I have seen large variations in how true the bed joints of masonry structures are to a horizontal line. How much should be tolerated?
The Masonry Standards Joint Committee's Specification for Masonry Structures (ACI 530.1/ASCE6/TMS 602) contains masonry tolerances. This document has been adopted by many building codes. Permissible variations from level for bed joints are listed in paragraph 3.3 F.2.a in the 1995 edition or 3.3 G.2.a in the 1999 edition. Bed joints may not vary more than ±1/4 inch in 10 feet or ±1/2 inch total.