Underpinning is a method used to stabilize and reinforce the foundation of a house or building. As buildings age or undergo natural effects such as settling, the foundation may require additional strengthening to prevent further damage and deterioration over time. Underpinning typically involves excavating the soil around the foundation in small sections and reinforcing the foundation by adding concrete or steel supports beneath it.
There are various methods of carrying out underpinning, and the specific method used will depend on the foundation's issues. In general, the process involves the following steps:
1. A section of the foundation is excavated, generally 1 meter at a time.
2. The soil beneath the foundation is carefully removed until the desired depth is reached.
3. Once the soil is excavated, concrete or steel supports are installed beneath the foundation to reinforce and strengthen it.
4. After the supports are in place, the soil is backfilled gradually until the foundation is secure.
Additionally, underpinning is often necessary due to environmental changes such as soil erosion or rising water tables, which can weaken the foundation. It can also be prompted by structural alterations made to the building, or to accommodate renovations like adding a basement. Proper assessment from structural engineers is crucial to determine the needs and requirements before underpinning begins, ensuring that the right method is applied to enhance stability effectively, and that local building codes are adhered to throughout the process. Overall, underpinning is an essential technique to ensure a building’s longevity and safety.