Engineer’s Advice: What is causing the brick walls in my house to crack?
You may have noticed that your house’s walls have started to develop cracks. This might have occurred during general maintenance, or perhaps a building inspector during the process of selling your house. It is a very common problem Brisbane and South-East Queensland in general, but requires careful management.
Why is it happening?
The cracks most often happen because of movement in the building’s foundations. Since a foundation forms the base of a building, if the foundation moves, anything that rests on it will also – this includes internal walls, external walls, suspended floors and roof members.
While you would expect solid materials such as timber, steel and concrete to stay stiff and not bend, their real-world performance is not the case. When placed under load, foundations will bend, and in more severe cases, break into multiple pieces.
This happens due to two main reasons:
- The soil below the foundation is not supporting the structure properly
- The foundation is defective
How do I assess the problem?
There is no exact formula for assessing the severity of the cracking/movement. Someone with a deep understanding of soil mechanics, local geology and construction methods is needed to determine the severity of the problems.
They will investigate:
- The size of the cracks
- The pattern of the cracks
- The manner in which the building is constructed
- External factors such as neighbouring properties
From this information, an accurate assessment can be made. What appears as a ‘small’ problem to a layperson may in fact be a major issue, while the opposite also often applies.
How do I fix the problem?
It is important that these defects be detected and managed early, as they will get worse over time. The relationship between the severity and cost of repair is not a linear one – that is to say that if the problem gets twice as bad, it will won’t cost twice as much to fix, it could cost four times as much.
Early detection and management is much, much cheaper than remedial works. Even if you do require remedial works, there are new, innovative solutions that are significantly cheaper than traditional methods. Have a structural engineer assess and advise you as soon as you start to see cracks and movement in any building.