Underpinning Your Home: Methods and Inspections

When you're undertaking underpinning work, it's absolutely vital to protect the structure overhead. This means every bit of excavation must precisely follow your engineer's instructions and detailed drawings. You must be careful not to dig out too much material from under the existing foundations, as this could cause more problems. The exact method you choose will always be tailored to your specific project's circumstances.

Be warned: incorrect underpinning carries serious risks. It could severely damage your property or even lead to its collapse. Given these significant dangers, we cannot stress enough the importance of bringing in seasoned professionals. You'll need experienced experts for the design phase, such as a qualified designer and a structural engineer. And for the actual construction, ensure you select a builder with a proven history in underpinning work and general building projects.

Often, underpinning is carried out in short, individual sections, one at a time. However, if a substantial part of your foundation needs attention, you might find it possible to work on several sections simultaneously. This is only permissible if those sections are spaced widely enough apart to ensure the stability of the existing building is not compromised.

Before you even think about pouring concrete for any underpinning section, expect both a design engineer and a building control surveyor to inspect the excavation. Why? Because just filling the dug-out area with concrete doesn't automatically mean the existing foundation will be properly supported; gaps can easily form between the old and new structures. To achieve true stability, you'll typically need to firmly pack any such voids with a sand and cement mix. This crucial packing process might also be subject to inspection by the engineer and building control surveyor.

Remember, the exact timeline for each step, and details about the materials you'll use, are specific to your individual project. Always refer to your structural engineer's design, as it will contain all these precise specifications.