Number 2 Building Defect -Wall Cracks

The 2nd most common building defect found during building inspection is wall cracks in internal and external walls. More than 40% of houses are plagued with cracks in the walls in Australia. Every house has wall cracks but most of the cracks are superficial and need to not be worried about. But some types of cracks could be dangerous for the building or maybe indicators of some serious issue underneath.

A building inspection can warn you about the major crack in the building and protect you from significant future loss. It is helpful to have an understanding of serious building inspections such as cracks in internal and external walls. Building Inspection Council has assembled the important information about building wall cracks.

Types of Building Wall Cracks

In broad terms, the cracks of the walls are 3 different types:

Superficial or Plaster Cracks: These superficial cracks are limited to the plaster depth only. These cracks can be ignored or patched and repainted for aesthetic purposes.

Medium or Brick Work Cracks: The cracks more than 15mm width,  diagonal or stepped fall in this type. There may underlying issues which may need immediate attention and progress with time.

Severe Cracks: The cracks in the critical parts of the building such as foundation or cracks wider than 25mm are severe in nature and need urgent building work.

1. What are the causes of cracks in the walls?

Poor Design or Construction: A building with poor design or construction will develop cracks over time due to over-weighted elements and inferior workmanship.

Settling or Subsidence: Excavation is required when building a new building and when this soil settles down over time, It causes cracks in the walls and other elements.

Climate Change: The seasonal change in the humidity and temperature leads to expansion and contraction of different parts of the building which results in cracks.

Reactive Soil: There are types of soils that react to change in moisture and expand or contract accordingly. This causes cracks in the building.

Water Damage:  The water damage from the leaking pipes, clogged gutter, or flooding is another reason for walls cracks.

Invasive Trees in Proximity: Trees near a wall can cause cracks through the invasive roots, altering moisture content of soil or physical damage to the wall.

Degradation of Building Material:  Building material with time does decay due to weather, gravity, rotting, or poor maintenance and leads to wall cracks in the building.

Excavation in Proximity:  If there is construction happening in close proximity of your building then crack can happen due to vibration or soil movement from the vibration and excavation. A dilapidation report can help the owner of the property in this situation. 

2. When are the cracks in walls are serious?

A visible crack is always a concern but all the cracks are not of equal concern. The cracks in the walls become alarming:

When cracks are wide enough: Any cracks under 5mm are superficial and are due to the settling of the building. But cracks more than 5mm are concerns and should be monitored. A crack more than 25mm is severe and needs urgent attention.

When cracks are run diagonally: Vertical wall cracks due to drying plaster but diagonal crack or stair shape cracks means structural defect such foundation movement, Termite infestation, water damage, etc.

When cracks are located above the door frame: Wall cracks do appear in the weakest portion of it such as around the window frame. But diagonal starting from the corner of the door frames are indications of building movement or other issues.

When cracks are see-through: Normally crack are visible only from one side but if the cracks are visible from both sides of the walls then it is a sign of underneath structural defect.

For detailed information on this topic, you can read “WHEN ARE THE CRACK IN THE WALLS ALARMING?

3. Where do cracks appear in the building?

At Building Inspection Council, we have observed that most of the cracks happen in the weak areas of the walls such as:

  • Around window frames
  • Around door frames
  • Joints of walls or wall junctions
  • Joint of ceiling and walls

The minor crack (limited to plaster) can appear anywhere in the walls and are vertical in nature.

4. How to fix wall cracks?

Fixing Cracks - Building Inspection CouncilMinor wall cracks (hairline cracks or cracks under 5mm) are negligible and not a cause of concern. These cracks can be patched up and re-painted to make it look nice again.

The cracks more than 15mm wide are the cause of concern and need remedial work to stop the progress of the issue from deteriorating. Building Inspection Council will advise seeking the help of professionals to rule out any serious underlying cause of the cracks.

Any severe cracks (more than 25mm wide) will require extensive building repair. The severe cracks pose the threat of collapsing the building or section of it. Fixing it may involve replacing the section of walls or section of the building. Other common fixtures of severe cracks are re-stumping, leveling, underpinning, demolition, and reconstruction, etc.

5. How much do wall cracks cost to repair?

Wall cracks repair is costly especially when the structural problem is involved. Wall cracks must be repaired immediately as ignored cracks worsen with time and will cost you much higher as compare to the beginning. Walls crack could be due to other issues underneath and Building Inspection Council has observed that usually these issues are serious and may make your home unsafe for living.

The irony is that your insurance may cover the cost of crack repair and underneath cause but you may be burdened with the cost of relocation and rent of the alternative property. It is advisable to fix the wall cracks as soon as possible to save money in the long run.

Inspecting Cracks - Building Inspection CouncilThe differentiating between a minor crack and major cracks or identifying the concealed cracks is not a cup of tea for an untrained property buyer even if you are a seasoned buyer. A professional building inspector is trained and have knowledge to analyze each crack and detect hidden cracks in the building. With experience, they know where to look and what to look for. This helps you with precise assessment of the property you are intending to buy.

Building Inspection Council is a not-for-profit community service and we help Australian property buyers with free quotes from local building inspectors to help you with wall crack. The best thing about being a not-for-profit organization is that we do not have compromised for profit. We provide the most genuine and honest quotes. FOR FREE  QUOTES, CLICK HERE

Number 2 Building Defect -Wall Cracks