Garden Basement Construction in London – From Excavation to Waterproofed Shell

At Delta Force Basements, we specialise in creating high-quality garden basements in London that add space, style, and long-term value to properties. One of our recent projects involved building a brand-new basement under a client’s garden, transforming unused ground into a fully waterproofed, structurally sound living area.

Step 1 – Precision Excavation

The project began with the excavation of the garden space, carried out with specialist equipment and safety measures. Working beneath an existing property requires accuracy, so our team used a phased excavation method to carefully remove soil while protecting the surrounding structures.

Step 2 – Structural Works and Underpinning

Once the excavation was complete, we moved on to the structural formation. Reinforced concrete walls, underpinning, and structural steel supports were installed to ensure the basement was built to last. Every stage was completed to strict engineering standards, guaranteeing stability and strength.

Step 3 – Basement Waterproofing System

Waterproofing is at the core of any successful basement project. For this garden basement, we installed a Delta cavity drain membrane system to the walls and floor. Alongside this, we fitted perimeter drainage channels and a sump pump system, providing continuous protection against water ingress and damp. This ensures the basement remains completely dry all year round.

Step 4 – Completed Waterproofed Shell

With the membranes, channels, and pumps fully installed, the basement was sealed into a dry waterproofed shell. This stage creates the perfect foundation for the client’s fit-out, whether they choose to turn the space into a gym, home cinema, office, or guest bedroom.

The Finished Result

By converting unused garden space, the client now has a modern basement extension that is both functional and future-proof. The waterproofed shell ensures peace of mind, while the structural works add lasting value to the property.

At Delta Force Basements, we provide end-to-end basement construction services across London, from excavation and underpinning to basement waterproofing and sump pump installation. Whether you’re planning a basement under your property or under your garden, we deliver secure, dry, and ready-to-use basements tailored to your needs.