What causes cracks in the walls of a home?

Typical causes of wall cracks include:

  • The house settling
  • Trees in close proximity to the home
  • Reactive soil
  • Water damage
  • Structural/design issues

Although the sight of cracked walls or architraves may be quite alarming, it’s actually very common.

The most common places for wall cracks are above doors and windows – this is because these are the weakest points of the wall. If the cracks appear to only be hairline cracks, they can be easily fixed with filler and repainted.

Settling in houses is especially common with new builds, this is because the timber used in the house frame often contains moisture and it can move slightly as it dries out, these cracks from settling are often very thin and vertical.

The Australian climate also, unfortunately, contributes to cracks in walls, our hot dry summers and lack of rainfall leads to the soil shrinking and moving and this places strain on the home’s foundation.

Whilst trees around the property are a beautiful feature, it is often not realised the damage that root systems can cause to homes. Trees with large, complex root structures can spread too close to the house’s foundations and lead to movement. Roots also change the water levels of the soil which can lead to instability within the soil. Before removing a nearby tree from your property you must also take into account that trees root system, removing a tree too close to the home can also change the water levels and stability of the soil.

When should I be worried about a crack in my walls?

If you notice any discolouration around the crack, you should immediately look to investigate. Discolouration around a crack can be a tell-tale sign of a leak somewhere within the walls, to fix this the source of the leak must be identified and the affected wall will need to be replaced to avoid further damage.

If the cracks are larger than a hairline, you should look to have them inspected. Large cracks (larger than 5mm) can indicate a structural problem. The shape of the crack can also shed light on the cause, a crack that appears in a zig-zag pattern can be an indicator of a structural issue as it is following the mortar line in the bricks.

Be sure to take photos and document the cracks in your wall as you notice them, this will be a good indicator of whether the cracks are getting worse or if they are staying the same.

If the wall crack seems like more than just a cosmetic issue, you should call an expert to investigate as soon as possible. The longer structural damage is left untreated, the harder and more expensive it is to fix.

Before trying to fix cracks or damage in your walls yourself, be sure to contact a structural engineer. Residential Engineering offers structural inspections in New South Wales, if you are worried about the cracks in your walls, call us today.