A split brick is a brick that delaminates into thin layers, usually as a result of too-rapid drying, faults during firing or frost damage; it is considered a quality defect.
The splitting occurs along internal planes of weakness in the clay. When a brick dries or heats unevenly, or when trapped moisture freezes and expands, internal stresses cause the material to separate into leaves. The result is a brick that flakes apart and cannot perform reliably in masonry.
Common causes
- Rapid drying: the outside dries and shrinks faster than the core.
- Firing faults: uneven temperature or trapped gases during firing.
- Frost action: water inside the brick freezes and expands.
- Poor clay preparation: layered structure left in the raw material.
Application
Recognising split bricks matters in quality control and durability assessment.
| Context | Concern |
|---|---|
| Delivery inspection | Rejecting defective bricks |
| Facing brickwork | Risk of flaking on exposed faces |
| Frost-exposed masonry | Progressive layer separation over time |
Split bricks are typically sorted out before or during construction, especially where they will be exposed to weather and freeze-thaw cycles. Using frost-resistant bricks and correct manufacturing greatly reduces the risk of this defect.
Related terms
- brick
- frost
- masonry
- building defects
- natural stone
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