Your structure is only as good as its foundation and as soil changes and alterations are made to older buildings, it is imperative to stabilize your foundation for the new build or addition. In structural engineering, underpinning is the process of strengthening and stabilizing the foundation of an existing building or structure. It’s necessary when undertaking renovation work in situations where the existing foundation is found to be inadequate, unstable, or unable to support the additional loads resulting from the proposed renovation. Underpinning is also used to repair foundations that have settled or deteriorated over time. Underpinning may be necessary in the following situations:
1. Foundation Settlement: If the existing foundation has settled unevenly, causing structural damage or creating an unsafe condition, underpinning can be used to stabilize the building and prevent further settlement.
2. Increased Load: When a renovation involves adding additional floors, expanding the building footprint, or making other changes that increase the load on the existing foundation, underpinning may be necessary to ensure the foundation can support the new loads. This may also be required to simply make a structure compliant with structural codes related to snow loads, wind loads or seismic concerns.
3. Foundation Deterioration: If the existing foundation has deteriorated due to factors such as soil movement, water damage, or poor construction, underpinning can be used to repair and reinforce the foundation.
Above: Our team hard at work ensuring compliance with structural engineering requirements.
Underpinning methods can vary depending on the specific requirements of the building and the underlying soil conditions. Common underpinning techniques include:
1. Mass Concrete Underpinning: This involves excavating sections beneath the existing foundation and pouring new concrete to increase the load-bearing capacity of the foundation.
2. Mini-Piled Underpinning: Mini piles, which are small-diameter piles, are installed beneath the existing foundation to transfer loads to deeper, more stable soil layers.
3. Jet Grouting: This method involves injecting grout into the soil to create a stabilized mass, effectively increasing the load-bearing capacity of the ground.
4. Screw Piles: Screw piles or helical piers can be used to support and stabilize the foundation by transferring loads to deeper, more stable soil or rock layers.
Underpinning is a complex process that requires careful planning, engineering expertise, and compliance with building codes and regulations. It is typically carried out by qualified structural engineers and construction professionals to ensure the safety and integrity of the renovated structure.
If you are in need of structural foundation work, reach out to our team and we can bring the right people in to ensure your project is set up for success.