This serves as a perfect example of the spandrel beam excessive deflection, which was translated into the brick veneer as the vertical crack.The problem is this building was designed in the early 1980s, when spandrel beam deflection had limits of L/360.If ground conditions are suitable, the use of an appropriate geophysical method can prove very economical in establishing some of the more important features of ground conditions on a large site, such as the depth to rock.
It advises vertical expansion joints in the brick veneer be located approximately 7.6 m (25 ft) apart in addition to the joints at each side of the exterior corner within 1.5 m (5 ft) from the corner.
Clay brick veneer of the masonry walls normally would have a moisture expansion and a thermal expansion/contraction, which should be absorbed by the brick veneer expansion joints.
Chapter 6, “Anchored Veneer,” of the standard has the following requirements for brick veneer: In Figure 1, a vertical crack had developed in the brick veneer in the middle of the large first-floor window.
It started at the window head shelf angle as a wide, open crack, and had disappeared as a hairline crack above.
To fix this problem, one must reinforce the spandrel beam, which would be an expensive proposition.
Another option would be to treat the crack as a movement joint, which means to brace the brick veneer on each side with masonry restoration anchors before sealing the fissure.The rods should be embedded into the raked joint with a soft grout; they should be located every three to six brick courses apart to reinforce the veneer.Other examples In Figure 2, one can see the horizontal crack in the parapet brick wall mortar joints at the roof level with approximately 6.4 to 9.5-mm (¼ to 3/8-in.) vertical displacement in the crack.For example, the moisture expansion of a 12-m (40-ft) long or high brick veneer panel could be calculated with the BIA formula: The moisture expansion behavior of the clay brick primarily depends on the raw materials and secondarily on the firing temperatures.Additionally, the clay brick’s moisture expansion is an irreversible process with most expansion taking place during the first months of manufacture, but expansion will continue at a much lower rate for several years.Dealing with cracks In this hypothetical example, crack development in the brick veneer was the evidence the expansion joints were not adequately provided to absorb the brick veneer movements.