
Luckily, wall cracks occur fairly frequently in new and older homes, often as a result of settling, and can be re-tapered to eliminate them quickly, and inexpensively. They can also signal serious structural problems that must be addressed immediately.
What Causes Cracks In Walls?
Is your building inspector flagging some cracks in the walls of your dream property in your dream location? Building inspections may detect serious structural failures in some cracks in the walls, whereas others are merely cosmetic in nature.
In a home, cracks in the walls can indicate structural issues. If you see an unsightly little crack in your living room wall, how can you tell if it will turn into a huge rift in the future? There might be a Grand Canyon of crack hidden behind those newly painted walls you saw at the open inspection.
Knowing whether you only need to add a little filler and paint to fix a wall crack is essential to determine if you require costly structural repairs. You might find yourself without a roof if you underestimate the seriousness of cracks in walls.
When Does A Crack In The Wall Suggest A Structural Problem?
Small wall cracks and hairline cracks may only be cosmetic, easily repaired with filler and paint. Cracks are not always a sign of a serious structural problem. A structural engineer should be consulted if large gaping large cracks indicate more serious structural or foundation problems that need foundation repair. Detailed information about cracking in your walls can be found in your building inspection report, some of which are discussed below.
Wall Crack Types
There are three main types of wall cracks:
- The plasterboard or gyprock of an interior wall is cracked (drywall cracks);
- Cracks in external walls such as brickwork, surfaces, or rendering;
- Foundation wall cracks.
Each of these can be a serious symptom of structural failure. The only way to determine how serious a problem is is to look at:
Cracked wall location;
- A jagged wall crack, a horizontal crack, or a vertical crack;
- Materials used in the construction of the wall or separation of the framework from the wall;
- The cause of the crack in the wall;
- If the crack cause is an ongoing issue likely to reoccur or a one-off.
The presence of gaping cracks indicates a serious structural issue. You may have a structural defect in your home if you have zig-zag cracks in the brick walls following the mortar line.
If the cement or mortar between bricks is completely separated, the problem might be particularly serious. As soon as you see through a crack or are able to wiggle or remove a broken brick, it’s time to call the experts.
Walls made of concrete are usually not prone to cracking, except after an earthquake when the foundation moves. It is normal for concrete walls to have hairline cracks. These cracks are usually not structural and can be filled in with a concrete repair caulk.
Internal Wall Cracks – What Causes Them?
During seasonal changes, wood framing can contract and expand slightly, causing small hairline cracks in plaster walls. In addition to cracks in internal walls, it is also possible that there are more significant and serious underlying issues as discussed further below, such as subsidence, a flawed original design, or a structural or foundation problem. Expert intervention may be necessary to repair cracks in the wall during building inspections, but insurance may not always cover the costs.
How Do Buildings Get Horizontal Cracks?

In plaster, fine hairline horizontal cracks can simply result from shrinkage, whereas more severe horizontal cracks are more likely to be caused by water damage. Building inspectors commonly identify horizontal cracks in foundation walls due to unbalanced soil pressure. Walls may also develop horizontal cracks due to pressure or load bearing problems, both of which are hazardous.
Cracked Walls And Their Causes: Signs Of Structural Damage
An assessment of the severity and cost of repairing cracked in wall begins with determining the cause of the cracks. Here are a few possible causes.
Subsidence And Settling
The first time a home is built, soil needs to be excavated. Different types of homes require different amounts of excavation work. It is necessary to disturb more soil during the construction of some types of homes than others. A wall will crack over time as disturbed soil becomes compacted and settles. Months or years may pass before this process is completed. The cracks that result from natural settling tend to be narrow rather than jagged.
It is normal for minor settling to occur over time. There may be structural faults under a wall if the soil moves downward (subsidence). A sudden flooding or a gradual leak can cause significant subsidence, or soil can compact too much or collapse. One of the most dramatic examples of this is sink holes.
Soil With Reactive Properties
Reactive soils expand rapidly when damp and contract when dry. A reactive soil is clay, for example. Sand and gravel are examples of non-reactive soils. Your wall cracks may be caused by reactive soil, which can be determined through soil testing.
Seasonal And Climate Changes
Wall cracking can be caused by seasonal changes and rapid changes in climate and events such as drought and flood.
Construction And Excavation In Your Area
Wall cracking may occur in areas such as new housing estates or near construction sites or quarries. All of these factors can cause your walls to crack, including vibration, blasting, heavy machinery, and excessive compaction of the soil. Your wall cracks should be assessed and legal advice sought as soon as possible if they appear sppm after construction occurs in your area.
Similarly, earthquakes and earth tremors can cause cracks in walls, though they are a relatively rare occurrence in Australia.
Extensions With Poor Construction Or Poor Design
It is also possible for walls to crack in poorly-designed or constructed parts of your property (e.g. an extension). The weight of a load-bearing wall can cause it to crack. Building materials that are inferior, faulty or flawed, as well as underengineered footing designs may also lead to wall cracks.
Damage Due To Water
The saturating or even washing away of soil can result from flood damage, blocked gutters, gardening sprinklers, and leaking and blocked pipes.
The property is surrounded by trees
Tree roots can also cause wall cracking because of their invasive nature. Keep shrubs and bushes away from your walls unless they are small. In addition to damaging roots, trees also affect the soil’s moisture content, which can lead to wall cracking.
In the space where the root system of a large tree once occupied, removing the tree may cause cracking in your walls because it can destabilize the soil. As a result, the soil’s moisture levels may change over time or it may settle.
Materials Degrading In Buildings
There is no such thing as a lasting building material. Building materials can be damaged by gravity, weathering, rot, or poor maintenance. The structural integrity of building material may be undermined when it begins to degrade, causing it to collapse. The result can be the appearance of cracks in the wall. Cracked walls can also be caused by concrete cancer. When you expose concrete reinforcements to moisture and salt, they rust and degrade.
My Wall Has Cracks, Are They Serious?

You can determine the seriousness of your cracking walls by observing their location, direction, and severity. You may be able to track the progress of cracks by taking photos and measurements over time. There can be serious safety risks associated with cracks in your wall. The wall could collapse soon if cracks are accompanied by popping screws or nails, leaning, tilting, or bowing. It is urgent to address these signs when they appear. A qualified building inspector can estimate the cost of repairing cracks in your walls after determining the severity of the cracks.
When You Should Be Worried About Wall Cracks
What are the signs that your wall cracks need to be addressed? It is possible to determine the severity of wall cracks by their location, direction, and extent. Wall cracks are often accompanied by other telltale signs of larger problems.
Doors and windows that stop working properly are a good indication of a structural issue. Your doors and windows might not open or close because of structural problems if they don’t stick or can’t be opened or closed.
There is also a sign that all is not well when nails pop or visible nails or screws appear in the walls. You should be concerned about cracks in ceilings, walls, and even the slab.
Uneven floors should raise alarms. A tilted floor line can be observed if you roll a ball across the floor.
It is possible for a wall to be twisting, leaning, or bowing, which may indicate an issue or may, in extreme cases, signal an imminent collapse. The safety of your family is at risk, so you should take action immediately.
Wall Crack Repair And Sealing: Fix Cracked Walls
There are a lot of ways to fix cracks in walls. Hairline cracks in walls can easily be hidden. Filler and paint can be used to repair or seal minor cracks that are nothing to worry about and are purely cosmetic.
However, if underlying structural defects are behind the cracks, then repairs may be more time-consuming, costly, and inconvenient. Waiting too long will increase the cost of the problem. The first step in addressing the underlying cause of significant wall cracks is to get an expert assessment. As part of the repair process, the following may be done:
When old steel, concrete, or timber stump rots, is attacked by termites or succumbs to corrosion damage, it must be replaced with a new one.
A house’s footings need to be stabilized by underpinning. Concrete can be injected into the site or poured into the foundation wall to raise it to its original level. In this process, your foundations will be excavated and new concrete will be poured or injected into the site.
Demolition and reconstruction: Where there is a serious structural defect behind wall cracks, it may be necessary to dismantle and rebuild a wall.
Your best options can only be determined by an expert. Multi-tradespeople, such as plumbers, builders, and tree loppers, may also be needed for this task.
The Cost Of Wall Cracking
In the event that a wall crack is an indicator that structural problems are involved, repairs can be extremely costly. You may find yourself with an condemned or uninhabitable home if you ignore wall cracks, though.
Repairing cracks or addressing the underlying causes may not always be covered by your insurance policy. Your mortgage commitments could be burdened with additional costs associated with relocation and alternative housing. In the long run, you will save money by repairing wall cracks as soon as you notice them.
Crack In The Wall – What’s Next?
Cracks in walls should be addressed as soon as possible. You can track the progress of cracks over time by taking photographs of them and including a ruler in the frame of the photo. Ensure that all obvious causes have been eliminated.
You should consult a qualified building inspector to determine the severity of the cracks in your walls and to determine the probable cause. It is possible for them to assist you with formulating a plan of attack and estimate your repair costs. Safeguarding your family and protecting your financial investment are of utmost importance.
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