Cracks in walls can be unsightly and the cause of concern for many homeowners and tenants. They can be a superficial problem, an eye sore but nothing serious, however they can also be an indication of a much more serious household problem you shouldn’t ignore.
A little crack can grow into something bigger over time and it can be challenging, not to mention expensive, to fix later on when significant damage has been done. It’s important to find out what is causing those cracks in the walls and repair them before it is too late. Here are eight common reasons why your wall is cracking.
Please note that the article provides general information only. For specific information and advice for your situation it’s best to get in contact with builder or building engineer
Common causes of superficial cracks (less than 5cm)
Superficial cracks are nothing to be concerned about. Small cracks on internal plasterboard walls can easily be fixed by a competent DIYer. Most repair jobs will only require a small amount of sand-able filler, putty knife, sand paper and paint and paint brush.
Temperature and humidity changes
The materials that make up your interior walls (commonly plaster, paint and timber) all tend to expand and contract slightly with sudden fluctuations in humidity and temperature which can result in minor superficial cracking on the interior walls of your home. These sudden changes are usually observed in rooms which are air conditioned periodically or in rooms which are exposed to a lot of direct sunlight.
Low quality products
Poor quality paint and plaster products tend to be less elastic and less tolerant to temperature and humidity changes which as mentioned previously can result in superficial cracks appearing on your walls. It’s best to ensure that you or your plasterer and painter and your use high quality products for maximum longevity.
Common causes of structural cracks
These are cracks which have compromised the foundations of the home and it’s best to seek professional assistance with these larger cracks.
Soil subsidence is the sudden sinking or gradual downward settling of the grounds surface with little or no horizontal movement. This is a major cause of cracked walls inside homes. Soil subsidence can have both natural and man-made causes. Cracks caused by soil subsidence can appear in both the interior and exterior of the building and often have a jagged appearance. Soil subsidence can result in structural weakening and potential safety risks. This must be inspected and repaired by a skilled expert.
House settling in
The cracks could be caused by the house settling in the soil. Before new homes are built, excavation is done to the lot area. The disturbed soil takes weeks even months to become compacted and settle. However, this process can cause cracks to appear on the walls of recently built homes. These types of cracks typically appear as narrow vertical cracks on the walls.
How these cracks are fixed will depend on where they are located, and the type of building material used to construct the home. Since these kinds of cracks appear shortly after construction it’s best to have the builder of the home come and inspect the cracks and perform necessary remedial work. Most reputable home builders offer a warranty so any remedial works should be performed free of charge provided it is done before the end of the warranty period.
Rainfall and storm water
The cracks in your walls could be directly or indirectly caused by natural causes, such as the changes in climate and seasons in your region. Rainfall and moisture from storm water runoff can cause the soil to expand and contract causing slight movements in the foundations of your home causing cracks to appear on the interior walls of your home. This is especially prevalent in areas which have reactive soils clay type soils which can expand and contract considerably as moisture increases and decreases.
Because storm water runoff can be concentrated in certain areas of your home this can lead to uneven rates of expansion and contraction. The result is the foundations of your home can become uneven and require levelling or underpinning to strengthen its foundations. This is no simple DIY task and best left to professionals.
Exterior water leaks
Water leaking from pipes can cause weakening and movement of the soil. Leaks can also wash away soil resulting in a softening of the ground leading to soil subsidence and resulting in cracks appearing. In order to properly address this issue a plumber may need to be called in to identify the origin of the leak, fix it and implement plumbing strategies to ensure the leak does not return in the future. Then remedial work can be done to the foundations of the house.
Destructive tree roots
Trees situated close to your property can become very problematic. The roots can directly press up against your home’s foundations causing movement and subsequent cracking. Trees can also prove to be problematic by indirectly by absorbing the water content from the soil affecting its moisture content in an isolated section of the building resulting in an uneven expansion and contraction as mentioned earlier. Prevention is always better than the cure, choose to plant small shrubs instead and ensure large tree are planted well away from the foundations of the home. If you’ve got a problem tree you’ll need to hire an arborist or landscaper to safely remove the tree without causing further damage to your property.
Building materials do not last forever. A lot of factors can contribute to its lifespan such as UV exposure, weather, rotting, poor maintenance, etc. When the building materials start to degrade the structures are can become destabilised causing the walls to crack. Concrete cancer is a common example of cracks developing in walls due to material degradation. Concrete cancer is when the steel reinforcements in concrete are exposed to moisture in the air and start to rust which causes the steel to expand resulting in the concrete cracking.
Whilst superficial cracks are simply an eyesore and can be repaired at a time convenient to you, structural cracks in your home must be taken care of as early as possible. It could be an early sign of a significant issue or poor house construction. When you notice a large crack in your home it’s best to get someone with the experience and expertise to inspect and determine what the root cause is. In this way, you can be sure that your walls remain strong and last a lifetime.
Paul is a professional plasterer who has over 15 years experience in the plastering industry. From simple wall repairs to complex shop fitouts Paul has experience in all things plastering related. He operates a small family run plastering company in Sydney called Paul’s Plastering. If you’re in need of a quality plasterer get in touch with Paul today!