Cracking in brickwork is a common issue in Perth homes. The type of construction in Perth is different to other parts of the country where the use of brick veneer and timber framing is more the norm. Most of the cracking seen in Perth homes is usually due to settlement of the structure over time. The loads placed on internal wall because of a conventional roof system also plays a part in the settlement process.
The Australian Standard for Pre-purchase Building Inspections 4349.1 categorizes cracks in masonry walls into 5 Categories. Anything over a category '2' should be inspected by an engineer.
0-Hairline cracking, less than 0.1mm,
1-Fine cracks that do not need repair, less than 1.0mm,
2-Noticable cracks, yet easily filled 1mm -5.0mm,
3-Cracks that can be repaired and possibly some of the wall sections will need to be replaced. Note weather tightness can be impaired, 5.0mm-15.0mm,
4-Extensive repair works required involving breaking out and replacing these sections. Walls can become out of plumb and fall and causes reduced bearing capacity, 15.0mm -25.0mm.