Vertical Brick Cracks

While concrete bricks inevitably shrink a little, clay bricks grow. The amount is variable, from about 0.3 to 1.6 mm/m over 15 years.
Significant brick growth tends to be a characteristic of certain types or bricks, such as wirecuts, or eras and this is will vary regionally. It is also usually accommodated by appropriate articulation (or “expansion”) jointing so we tend to only see such cracks when jointing is inadequate. As with most distress cracks these can be combined with other mechanisms. Figure 1 shows a common presentation. While it is not uncommon for brick growth cracks to occur in other locations, it is uncommon for them to be other than fine vertical cracks.