What spacing should be used for brick expansion joints?

ASTM C 67 contains a freezing and thawing test which is presently the industry accepted standard. This test should be conducted prior to delivery of brick to the job site. Bricks pass the test if, after 50 freeze/thaw cycles, they do not exhibit significant weight loss, breaking, or cracking. The test is designed to be performed on brick that have not yet b een built into a wall.

There are many factors that contribute to brickwork's ability to withstand cyclical freeze/thaw including workmanship; the mortar type, its air content and consistency when laid; and the degree of saturation in a wall. These factors cannot be tested for in ASTM C 67 since they involve other elements outside the brick itself. 

Consequently, it is not a forgone conclusion that a brick that passes the test will not experience adverse effects when incorporated into brickwork. Attention to proper design, detailing and workmanship can assure a durable wall assembly.