Soil subsidence refers to the process of the earth sinking. If a building is constructed above this subsiding soil, the structure also becomes affected as it sinks along with the soil. Building subsidence can occur in varying degrees; nevertheless, it is still a serious concern. This is why soil testing is prudent before embarking on construction. By opting for soil testing, your contractors can advise you on whether the land is viable for construction or determine if they would need to opt for specialised techniques in the construction of your foundation.
What are the causes of building subsidence?
A misconception that some people may have about building subsidence is that it is exclusively related to the type of soil on your land. Although some soils may be more suitable for construction than others, this is not the only cause of building subsidence. Some of the other causes of building subsidence include:
- Loosely compacted soil—especially in sites that were used as landfills because the soil will not have settled fully
- Collapsing of soil
- Slippage of soil
- Continuous erosion of soil
- Increased moisture content in soil
Engaging in soil testing ensures that your surveyor can pinpoint the exact cause of soil subsidence on your property. This enables them to prevent any potential problems that may arise by constructing on the affected soil without prior measures being taken to arrest the soil subsidence.
Signs of building subsidence
In some cases, you may be contemplating house demolition or renovations in an attempt to update the structure. However, if the previous structure was suffering from building subsidence, then it is highly likely your new structure will be affected too. Thus, it would be essential to look out for any warning signs of building subsidence. Some of the signs to be wary of include:
- Door and windows that keep sticking to their frames. The most common reason for this is a change in the frame's adjustment due to the structure moving, which would be caused by soil subsidence.
- Extensive cracks forming on the walls of the structure.
- Ripples in the wallpaper, which would come about because of moisture permeating the walls due to the compromised foundation.
If your current structure is exhibiting these signs, then you should consider having a soil test done. In some cases, the cause of the building subsidence can be due to the weather conditions. For example, if the topsoil is exposed to significant drought followed by heavy rainfall, it will contract. This, in turn, will affect the structural integrity of the foundation.