Basement Underpinning & Waterproofing specialists
We design, construct, and waterproof beautiful, durable basements for homes across London. Trusted by homeowners for quality, craftsmanship, and care.
Why Choose Delta Force
Comprehensive Site Excavation & Preparation
We begin with precise grading and soil removal, using laser-guided equipment to achieve the exact depth and footprint your project requires. From day one, our team ensures safe access, erosion control and proper staging areas—so every square foot of your future basement is built on a solid foundation.
Expert Structural Formwork & Reinforcement
Once excavation is complete, we install heavy-duty formwork and place rebar to engineering specifications. Our crew works closely with your structural engineer to confirm footing dimensions, tie-in details and load-bearing placements—guaranteeing a shell that meets or exceeds local building codes.
High-Strength Concrete Pour & Curing
We use premium, low-shrinkage concrete mixes designed for below-grade applications. Pours are scheduled for optimal temperature and humidity conditions, and we monitor curing with moisture sensors to prevent cracking. The result: a uniformly solid wall and slab ready to stand up to hydrostatic pressure.
Precision Joint Treatment & Crack Control
Prior to waterproofing, we treat control joints and construction joins with flexible sealants and waterstop embeds. This preemptive approach minimizes the risk of future leaks and creates a seamless interface between concrete pours.
State-of-the-Art External Waterproofing
We apply a multi-layer system—typically a robust membrane (peel-and-stick or spray-applied) plus a protective drainage board. This “armor” shields your basement walls from ground moisture and redirects any seepage toward the perimeter drain.
Perimeter Drainage & Sump Integration
Around the footing, we install a dedicated drainpipe encased in clean aggregate, sloped precisely toward a high-capacity sump basin. This ensures any water reaching your foundation is swiftly collected and routed away, keeping the interior dry under all conditions.
Final Backfill & Site Restoration
After waterproofing and drainage are in place, we backfill with free-draining material, compacted in lifts to prevent settling. Our team then restores grading and installs temporary erosion controls—leaving your site neat, safe and ready for the next contractor.
Ready-for-Trade Handoff
We deliver a watertight, structurally sound basement shell—complete with engineer-stamped as-built drawings, waterproofing certificates and drainage test results. Your chosen trades (framing, electrical, plumbing, finishes) can step in immediately, confident that the below-grade work is fully
By specialising exclusively in shell construction, Delta Force Group eliminates the guesswork and headaches of below-grade work. You get a single point of accountability for excavation, structure, waterproofing and drainage—so your general contractor or homeowners can focus on the finish line, not fight leaks or delays. Choose Delta Force Group and start your project with a truly solid, water-tight foundation
Basement shell construction
Build a solid, long-lasting basement shell using high-strength reinforced concrete and quality formwork techniques. Our process includes precision excavation, steel reinforcement placement, and expert concrete pouring to create a watertight and structurally sound foundation.
Waterproofing systems
Safeguard your basement against water infiltration with advanced waterproofing solutions. We install exterior membranes, drainage board systems, and integrated interior drainage channels. Combined with high-performance sealants and coatings, these systems provide comprehensive protection against hydrostatic pressure.
Underpinning & Foundation
Underpinning & Foundation Stabilization Address settlement and load-bearing issues with professional underpinning services. Utilizing methods such as mass concrete underpinning, mini-piled underpinning, and helical piling, we stabilize and reinforce existing foundations to support additional loads and prevent further movement.
Drainage & Soil management
External Drainage & Soil Management Control groundwater and surface water with engineered drainage systems. Our services include perimeter French drains, perforated pipe installation, and soil grading to direct water away from the foundation, reducing hydrostatic pressure and minimizing erosion.
Structural repair & Crack Injection repair
Structural Repair & Crack Injection Repair structural defects and seal cracks with precision techniques. We perform epoxy and polyurethane injection to fill voids and restore concrete integrity. Carbon fiber reinforcement and steel plate installation provide additional strengthening for weakened areas.
Vapor barrier & Moisture control
Vapor Barrier & Moisture Control Maintain a dry basement environment with professional vapor barrier installation. Our high-density polyethylene membranes and protective coatings prevent soil moisture migration and vapor transmission, preserving air quality and structural materials.
Sump Pump system
Integrated Sump & Pump Systems Enhance moisture management with integrated sump pit and pump installations. We design and install robust sump systems equipped with battery backup options and high-capacity pumps to handle peak water inflow and ensure continuous operation during power outages.