When it comes to underpinning foundations in London, the process involves supporting or strengthening the foundation of an existing house, building or similar structure. When underpinning a house, this is accomplished by reinforcing the existing foundation, strengthening the soil by introducing an expanding filler, or extending the foundation so that the load is distributed over a greater surface area.

 

Underpinning: When is it needed?

For a majority of homeowners, underpinning a house in London is something that is required when the original foundation is not strong enough to support the house. This is usually a result of one of:

 

-Underpinning can be needed when the soil supporting the foundation has changed in some way e.g. through subsidence, expansion/contraction due to moisture, large trees nearby, damaged plumbing left unrepaired. 

-Our underpinning contractor in London often does underpinning when the properties of the soil were not adequately understood during the original design of the foundation – meaning the foundation is not adequate for the conditions.

 

In less common cases, underpinning is also required for the following reasons:

-The way the structure is used has changed e.g. following a major renovation, meaning underpinning is needed

-Some underpinning in London is based on construction nearby resulting in the excavation of soil supporting existing foundations

-To increase the capability of existing foundations e.g. to support another storey to the building

-Some of our underpinning foundations work in London is due to natural disasters such as earthquakes, floods or droughts that have caused the structure to move or become unstable.

 

When it comes to repairing the foundations on buildings with stumps, the method used is referred to as restumping or reblocking. Essentially this involves replacing the foundation stumps when they are cracked or otherwise damaged. This is not considered underpinning. Within this definition of underpinning work on London sites, there are three methods in use today:

• Concrete Slab
• Screw Pile
• Grout or Resin Injection