Underpinning & Structural Strengthening in London

Reinforcing Existing Foundations for Safety and Stability

Delta Force Group Ltd specialises in underpinning and structural reinforcement for residential and commercial buildings across London. Whether you're strengthening an old property or preparing for basement construction, we deliver safe, engineered solutions that protect your structure long-term.

🔧 What Is Underpinning?

Underpinning is the process of strengthening and stabilising the existing foundations of a building. It's often required when:

  • The original foundations are failing

  • The soil beneath has shifted or weakened

  • You're extending the basement or adding floors

  • Cracks are forming in the walls due to subsidence

  • Building regulations require deeper or reinforced support

Book a Free Basement Survey Today

Looking for expert basement construction, waterproofing, underpinning, or groundworks in London? Delta Force Basements deliver reliable, high-quality results to a waterproof shell – ready for fit-out.

Contact us now:
Delta Force Basements
Tel: 020 8092 0756
Mobile: 07405 046475
Email: groundworkcontractors@hotmail.com
Opening Hours: Mon–Fri 08:30–18:00, Sat–Sun 09:00–14:00

We provide free surveys across Greater London. Get in touch today and let’s start your project.

🛠 Our Underpinning Methods

We tailor each project to your building's needs, using:

  • Mass Concrete Underpinning – A traditional, proven method involving staged excavation and concrete pouring beneath footings.

  • Beam & Base Systems – Reinforced concrete beams spanning weak areas with solid pad bases for added support.

  • Mini-Piling – Ideal for restricted access or poor ground conditions, we install small-diameter piles to transfer load to deeper, stable strata.

  • Needle Beams & Temporary Props – Installed for load redistribution during excavations or basement conversions.

  • Crack Stitching & Structural Repairs – Strengthening of cracked or bowing walls using bars, resins, and ties.

🔍 Signs You May Need Underpinning

  • Large or widening cracks in walls or ceilings

  • Uneven floors or sagging areas

  • Doors or windows are sticking or misaligned

  • History of ground movement or subsidence

  • Planning a basement or major structural change

✅ Why Choose Delta Force Group?

  • Over 15 years of underpinning and groundworks experience

  • Work overseen by qualified structural engineers

  • Fully insured and health & safety compliant

  • Fixed-price contracts and detailed method statements

  • Trusted across London by homeowners, architects, and developers

When is underpinning required?

Underpinning is required when a building’s foundations are not strong enough or have been compromised. Common reasons include subsidence, new basement construction, extension works, or nearby excavation.

What underpinning methods do you use?

We carry out a range of methods, including mass concrete underpinning, beam and base systems, and mini-piled underpinning. The best method is chosen after a site survey and the engineer’s design.

Is underpinning disruptive to my property?

No. Underpinning is completed in carefully planned stages called bays. This allows the structure to remain stable throughout the works while keeping disruption to a minimum.

Do you provide engineer’s drawings and method statements?

Yes. All underpinning projects are supported with full structural engineer’s drawings, calculations, and method statements, ensuring compliance with building control and safety standards.

Contact Us Today for Your Underpinning Needs

Whether you need underpinning for a new build basement or a height extension for an existing basement, Delta Force Basements is here to help. Contact us today to discuss your project and get a free quote.