Know when to worry about cracked walls in your home.

Everyone knows how to fix hairline cracks, but what about larger cracks? When should you be concerned?

Cracks in walls are a common occurrence and most are just hairline cracks that require fixing without too much effort. It's when cracks are wider or specifically placed that you need to worry and consider calling in an expert to investigate. Most brick and plaster homes experience small cracks in walls over time and these are perfectly normal due to settling of the house on the ground.

Here are some general causes for cracks that you don't need to worry about apart from fixing them:

What causes fine cracks in walls:

Newly built brick and plaster homes, including any new additions or extensions, are guaranteed to have a few minor cracks or hairline cracks as a result of settling. As the foundation settles and the mortar and plaster shrinkage there is bound to be some movement and wall cracks that occur

Houses located close to a busy road or nearby building sites may experience cracks caused by vibrations. Even though vibrations are small, they pass through the ground as they disperse, and this can result in hairline cracks that regularly appear.

Poor building practices can also be blamed for cracks in a house, particularly where houses are not built to code or local municipal regulations. It could be that no concrete lintels (supports) were installed above windows, doors, and wall openings, or it could be that the foundations were not compact enough. There are many causes where bad building practices can come to light once you move into a property, which is why it is essential that you confirm that any building work is guaranteed and for how long.

Cracks to be concerned about

Having said that hairline cracks are nothing to worry about, there are some cracks that you need to take seriously and not wait too long to call in an expert to inspect. A structural engineer will be able to assess the type of crack and what has caused it and be able to offer advice on who to call to have the problem sorted. Keep the below points in mind according to their level of severity:

- Minor

Hairline cracks and cracks with a width less than 1.5mm can be easily fixed by chasing out the crack and filling with crack filler. 

With the proper preparation to fix hairline cracks - these should not be a nuisance in the future.

- Moderate

Any cracks that are wider than 1.5mm but less than 2.5mm may require professional repair unless you are willing to do this yourself.

Never ignore cracks with a width of more than 2.5mm or those that are horizontal as these are a sign of structural damage.

- Severe or Horizontal

Cracks that are wider than 2.5mm are an indication that there is a serious structural issue that could require extensive repairs. Cracks that are horizontal or horizontal in nature are usually caused by structure movement, especially if the cracks are wider than 2.5mm.

Action to take when discovering cracks.

It is always wise to investigate cracks as soon as they appear whether small or large with the exception of hairline cracks. If you are in a newly built property, discuss the cracks with the builder or developer handling the project. If you are in a rental property, take pictures and forward these to the letting agent or landlord to ensure you are not held responsible.

Continue to monitor cracks that appear to see if there is ongoing movement or if the cracks have stopped. Any cracks that continue to spread out should be investigated. Take pictures of the cracks when they appear and track them once a month or until they reach a size where you need to be concerned.