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Underpinning existing foundations

What is Underpinning?

As underpinning groundworks contractors in London, we are experienced in high quality underpinning. Underpinning is the building process of reinforcing current foundations when the subsequent project work is designed to create further loads on the wall, or to strengthen falling foundations. 

Why Underpin?

If you’re planning underpinning in London, for a wall on which you plan to build, underpinning foundations can be a way to repair to address signs of subsidence. Our experienced underpinning groundworks contractors in London can extend foundations in depth or width, allowing the wall to rest on more supportive soil stratums, distributing loads across greater areas. 

Use of micropiles and jet grouting for underpinning foundations in London is becoming a common method, though underpinning in London includes alternative options, such as strengthening soil with special grout or  expanding urethane-based engineered structural resins.

Types & Methods of Underpinning

As an experienced underpinning company in London, we use five main types of underpinning: 

Mass Concrete Underpinning 

Perhaps the most traditional method, having been used for over 100 years, underpinning London properties like this includes diggin boxes beneath walls, by hand, and pouring concrete sequentially and strategically. As underpinning contractors across London can attest, this adds an additional layer of foundation underneath existing foundations. 

Beam and Base Underpinning

Based on the mass concrete methodology, underpinning foundations that use this method include a reinforced concrete beam being constructed below, above, or in replacement of existing foundations. When our underpinning contractors in London use this method, it allows the beam to transfer the load of the building to mass concrete bases built at specific load bearing locations. 

Mini-piled Underpinning 

A more versatile method for underpinning in London, it is used where there are variable ground conditions, with restrictive access, and where pollution is a significant factor, and where structural movements services are  limited. 

Mini-piled Underpinning Schemes

As above, mini-piled underpinning in London properties includes pile and beam, cantilever pile-caps and piled raft systems. Used to avoid disturbing building interiors, cantilevered pile-caps are used for underpinning foundations, requiring the construction of tension and compression piles to each cap. 

Underpinning by Expanding Resin Injection

Another of our methods as an experienced underpinning company in London, this uses a mix of structural resins and hardener, injected into the foundations beneath existing footings. The expansion element of the process occurs when a chemical reaction happens between the resin and hardener on entering the ground.

Underpinning a Party Wall

On many occasions, when underpinning foundations in London properties, a wall shared between neighbours will need underpinning, for repair or to strengthen. Be aware of the potential risk of having no Party Wall Agreement as this could lead to significant legal costs by way of an injunction and claims of damage.

Looking for underpinning work to be done in London? Need help with Party Wall Notices and Surveying? We are an experienced underpinning company in London, ready and able to help you. Call us today.

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