What is the acceptable vertical tolerance allowed in CMU and brick construction?
1/8\" in 10ft and 1/4\" in 20ft?
Acceptable vertical tolerances in cmu and brick are covered in TMS 402/602 Building Code Requirements and Specification for Masonry Structures. The specific location is TMS 602 Part 3 paragraph 3.3 F.2.b. It allows for a +/-1/4" in 10 lf, +/- 3/8" in 20 lf and a 1/2" maximum. Remember when checking these tolerances that the TMS 402/602 may not be the best from an atheistic standpoint. The architect can put tolerances in the project specification that are more stringent than given in the code. They may also reference documents from BIA or NCMA. Read your specifications very carefully to insure that what is stated in the specifications won't require workmanship of a higher level (more costly). Brick workmanship should always be approved using a mockup.
Remember!! There is no ASTM standard for acceptable masonry workmanship.
Jerry Painter, FASTM
Don Beers, PE, GC
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