Noticed a crack in the wall of a property you’re considering buying? Don’t panic! Many cracks in walls are harmless, but some can indicate serious structural issues. As experienced building inspectors, we’ve seen all kinds of cracks – some that are just cosmetic and others that require urgent professional attention before purchasing a home.
Cracks in walls are a common concern for homebuyers, especially in Townsville’s climate, where temperature fluctuations, moisture levels and foundation settling play a role. In this guide, we’ll walk you through how to identify different types of cracks, assess their severity and determine when it’s time to call in the experts at Twin Cities Building & Pest Inspections (TCBPI) before you commit to buying a property.
Understanding the Basics of Wall Cracks
Not all cracks are created equal. Some result from natural settlement, while others signal structural problems that need urgent attention. Knowing the difference can help you make an informed decision about a property purchase.
Common causes of cracks in walls include:
- Natural settlement as a home ages
- Moisture fluctuations causing materials to expand and contract
- Temperature changes leading to thermal expansion
- Foundation movement due to soil conditions or poor construction
- Structural stress from renovations or heavy loads
In Townsville, homes are built with different materials, including brick, block, render and plasterboard. Each material reacts differently to stress, which affects how cracks appear.
Types of Wall Cracks: Identification and Assessment
Cracks in walls come in many forms and while some are purely cosmetic, others could indicate serious structural issues. The location, size and pattern of a crack can provide valuable clues about its cause and severity. Below, we break down the most common types of cracks in walls and what they may mean for a property’s structural integrity.
Hairline Cracks
- Less than 1mm wide
- Common in newly built homes due to settling
- Usually not a cause for concern but should be monitored
Vertical Cracks
- Often caused by foundation settlement or shrinkage
- Can be harmless if small but should be monitored for widening
Horizontal Cracks
- A potential red flag indicating foundation or structural movement
- Often caused by lateral pressure or shifting foundations
- Should be assessed by a professional
Diagonal Cracks (45-degree angle)
- Can be a sign of foundation movement or structural stress
- Often appear near windows and door frames
- Requires monitoring and possible intervention
Stair-Step Cracks
- Common in brick and block walls
- Usually indicates foundation movement
- A professional assessment is recommended
Large Ceiling-to-Wall Cracks
- May signal structural damage
- If accompanied by sagging, seek immediate professional evaluation
Assessing the Severity of Wall Cracks
Identifying cracks in walls is only the first step – understanding their severity is crucial when considering a property purchase. As experienced building inspectors, we’ve seen how minor cracks in walls can be early warning signs of larger problems. Evaluating the width, location, direction and progression of cracks will help determine whether they pose a risk to the integrity of the home.
How can you tell if a crack is serious? Consider these factors:
Width: Cracks wider than 3mm (1/8 inch) should be inspected. Cracks over 5mm often indicate underlying structural issues.
Location: Cracks near windows, doors or load-bearing walls are more concerning.
Direction: Horizontal and diagonal cracks are typically more serious than vertical ones.
Growth Over Time: If the crack is getting wider or longer, it’s time to investigate.
Other Warning Signs: Sticking doors, uneven floors or cracks forming in multiple locations could point to a structural issue.
Causes of Wall Cracks
Cracks in walls don’t just appear out of nowhere – they develop over time due to various factors affecting a home’s structure. As a homebuyer, understanding the root causes of these cracks is essential in determining whether they’re a minor cosmetic issue or a sign of deeper structural problems. Some causes, such as natural settling, are normal, while others, like foundation issues or moisture damage, can indicate serious concerns. Identifying the cause of cracks early can help you make an informed decision before purchasing a property.
Normal settlement – Especially in new homes as the foundation adjusts.
Expansive soils – Some Townsville areas have soil that shifts with moisture changes.
Moisture fluctuations – Rain, flooding, or leaks can weaken walls.
Poor construction – Substandard materials or shortcuts in building can cause instability.
Foundation issues – Shifting soil or erosion can lead to structural movement.
Tree roots – Roots growing too close to the home can affect foundations.
Termite damage – Weakened timber can cause walls to crack (ask about our termite inspections!).
When Should You Be Concerned?
Cracks in walls are common, but not all of them require immediate concern. As a homebuyer, knowing how to differentiate between cosmetic cracks and structural issues can save you from unexpected repairs. Below, we answer key questions about structural cracks, acceptable cracks, and insurance coverage.
How Do You Know if a Wall Crack is Structural?
Here’s how to tell if a crack might be a sign of something more significant:
- Wider than 3mm (1/8 inch) or 5mm – The wider the crack, the more likely it is to be structural.
- Horizontal or diagonal orientation – These types of cracks often suggest foundation movement or structural stress.
- Growing over time – A crack that is increasing in size indicates ongoing movement and should be monitored.
- Located near load-bearing walls or openings – Cracks around doors, windows, or at the junction of walls and ceilings can suggest shifting in the structure.
- Accompanied by other signs of structural movement – If doors or windows start sticking, floors become uneven, or multiple cracks appear in different areas, the issue may be more than superficial.
What is an Acceptable Crack in a Wall?
Not all cracks mean trouble. Some are part of the natural settling process of a home and are not structurally significant. Acceptable cracks include:
- Hairline cracks – Fine, thin cracks (less than 1mm) that appear in plaster or render due to minor shrinkage or settlement.
- Stable cracks – If a crack hasn’t changed over time, it’s less likely to be a structural concern.
- Minor vertical cracks – These are often caused by natural settling and are usually not an issue unless they widen or grow.
Even if a crack seems minor, it’s a good idea to monitor it for changes. If you’re unsure, getting a professional assessment can provide peace of mind.
Does Building Insurance Cover Cracks?
Insurance coverage for cracks in walls depends on their cause. Generally:
- Covered: Sudden events such as earthquakes, storm damage, or vehicle impact.
- Not Covered: Normal settlement, wear and tear, poor maintenance or gradual foundation movement.
If you’re purchasing a home and notice cracks in the walls, it’s best to consult your insurance provider about potential coverage. Always check your individual policy details to understand what is and isn’t included.
DIY Repairs vs. Professional Solutions
While hairline cracks can often be patched with filler and paint, structural cracks require expert assessment. Attempting to repair significant cracks yourself could mask a bigger issue, leading to costly repairs later.
If you’re considering purchasing a property with cracks in walls, it’s always best to consult a professional to determine the cause and ensure you’re making a sound investment.
TCBPI: Your Local Wall Crack Assessment Experts
At Twin Cities Building & Pest Inspections, we specialise in identifying and assessing structural issues, including cracks in walls, before you buy a property. Serving Townsville, Ingham, Cardwell, Ayr, Charters Towers and Bowen, we provide detailed reports so you can make informed decisions about your potential home purchase.
Protect Your Investment – Call TCBPI Today
Cracks in walls shouldn’t be ignored when buying a home. Whether it’s a minor issue or a sign of something more serious, getting a professional inspection before purchase is the best way to ensure the property’s structural integrity.
Don’t take chances – contact us today! Call (07) 4723 2770 or book an inspection online to ensure your future home is safe and structurally sound.
