Basement Construction
Unlock the potential beneath your property. Expert excavation, retrofitting, and structural waterproofing services.
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Basement conversions and new build basements are among the most complex engineering challenges in construction. LG Groundworks specializes in the structural shell and core of these projects, providing a watertight, structurally sound foundation for your living space.
We handle the entire subterranean process, from the initial mass excavation and temporary propping to the installation of reinforced concrete (RC) shells and comprehensive waterproofing systems. Our team is experienced in working under existing structures (retrofitting) and ensuring the stability of neighboring properties.
Key Capabilities
- Basement Excavation & Bulk Dig
- Underpinning (Sequenced)
- Reinforced Concrete (RC) Shells
- Temporary Works & Propping
- Waterproofing (Type A, B & C)
- Sump & Pump Installation
- Lightwells & Light Scoops
- Party Wall Compliance
Waterproofing & Tanking
A dry basement is non-negotiable. We implement robust waterproofing strategies in line with BS 8102:2009. This typically involves a combination of barrier protection (Type A), structurally integral protection (Type B - waterproof concrete), and drained protection (Type C - cavity drain membranes), ensuring a dual-layer defense against water ingress.
Going Underground
A calculated, sequenced approach to structural safety.
Design & Support
Installation of temporary propping to support the existing house. Careful planning of the excavation sequence.
Underpinning
Excavating beneath existing walls in small sections (pins) and filling with concrete to extend the foundation depth.
Excavation
Removal of the central earth core (bulk dig) using conveyors or hoists, reaching the new floor level.
Shell & Waterproof
Pouring the reinforced concrete slab and walls, followed by the installation of the tanking/membrane system.
Basement FAQs
Yes. Basement works almost always affect the structural support of neighboring properties. You must serve a Party Wall Notice under the Party Wall Act 1996 before work begins.
Retrofitting involves digging out a basement under an existing house, requiring underpinning. A new build basement is constructed as part of a fresh project, usually involving an open excavation before the house is built above.
We use a combination of waterproof concrete and Cavity Drain Membrane systems (Type C). This system channels any water behind the walls into a sump pump, which then ejects it from the property, ensuring the internal space remains dry.