Types of Cracks
Not all wall cracks are equal. Understanding the type of crack helps determine the appropriate response:
Hairline Cracks
Very fine, surface-level cracks that are often cosmetic and minor. These typically result from normal thermal movement or plaster shrinkage and do not indicate a structural problem.
Vertical Cracks
Vertical cracks can indicate movement or settling in the building. While they are not always serious, they should be monitored and assessed if they are widening or accompanied by other signs.
Horizontal Cracks
Horizontal cracks are more concerning and can indicate structural issues including soil pressure on walls, foundation failure, or load-bearing problems. These require prompt professional assessment.
What Causes Wall Cracks?
Wall cracks can develop from a range of underlying causes:
Building Movement
Seasonal changes cause materials to expand and contract, leading to cracking over time.
Foundation Settlement
Gradual or differential settlement can cause walls to move and crack as the structure adjusts.
Moisture Changes
Water ingress or prolonged drying out of subsoils can alter soil volume and affect foundations.
Poor Workmanship
Inadequate construction methods, missing control joints, or substandard materials can cause premature cracking.
When Should You Be Concerned?
Cracks that are minor and stable may only need cosmetic repair. However, cracks may require professional attention if they:
- Are visibly widening over time — a sign of active movement
- Run diagonally — often associated with differential foundation settlement
- Appear suddenly — particularly following heavy rain, drought, or nearby construction
Repairing Cracks Properly
Effective crack repair is more than simply filling the gap. A proper repair involves a three-step approach:
Identify the Cause
Understanding why the crack has formed determines the correct repair method. Filling a crack without addressing the cause will result in it reappearing.
Stabilise the Structure
Where structural movement is involved, the underlying issue must be stabilised before any cosmetic work is undertaken.
Repair Finishes
Once the cause is resolved and the structure is stable, finishes — plaster, render, paint — can be repaired to a high standard.
Building Repairs Melbourne
If you have cracks in your home, these issues often require professional building repairs in Melbourne to address the underlying cause — not just the surface. We assess the root cause, stabilise the structure and deliver lasting repairs.
For more serious cracking associated with movement or foundation issues, this will often require structural repairs in Melbourne to properly resolve.
View Our Building Repair ServicesFor more information on the types of repairs we carry out, visit our building repairs Melbourne page, which details our structural, water damage and rectification services.
Need a Crack Assessment?
Contact Brownlow Building to inspect your property and determine the cause and extent of cracking.