Underpinning in Surrey, Sussex, Kent and all Counties in the Surrounding South East Area
Underpinning is a construction technique used to stabilise properties suffering from subsidence. Following subsidence, a property will require more structural support. Underpinning strengthens weak foundations. The process sees our contractors excavating soil that has started to move away from the build and compromise the support. Subsidence weakens the original foundations and eventually causes the property to move. We can replace excavated soil with deeper footings and stronger materials to stabilise and enhance structures.
This is a service that we offer to clients in the surrounding counties of Berkshire, Buckinghamshire, Hampshire, Kent, Surrey and Sussex.
Indicators of subsidence can include the following:
- Cracks in the walls, floors, ceilings and joists
- Sloped walls, floors and ceilings
- The property leaning to one side
- Doors and windows won’t close property
- Gaps between bricks, doors and framework
These signs can also indicate a property has already been underpinned.
Traditional Mass Concrete Underpinning
This underpinning technique can strengthen or deepen the foundations of an existing property, or we can produce a design specification that covers both. In addition to builds that have subsided, moved or suffered a failure in the foundations, contractors also use this method to accommodate additional loads if the existing foundations have an inadequate structural strength.
We use mass concrete underpinning up to depths of 2m. The excavation of ground sections below the existing foundations allows for the formation of deeper foundations. Our contractors create a controlled environment and work in stages so that the property always has a sufficient amount of support.
Piled Underpinning Raft Foundations
Should traditional mass concrete underpinning be unsafe due to the depth of excavation needed, we can introduce an internal piled solution instead. A piled underpinning method with raft foundations is used at shallower depths. This method requires the structure to be supported by adjustable steel jacks which, once they are in place, will then allow the raft to be constructed.
The raft is projected underneath the load-bearing walls.
Terminating the new slab 75mm beneath the footings and masonry, our team then compacts with a cement and sharp sand mix to accommodate the load transfer. As a part of our full package service, Horner Foundations can offer a design and construction specification to meet contract requirements.
Another method of underpinning is the beam-and-base method, where we construct RC ground beams above, below or to replace the footings.
With more than 30 years of experience, and with our own structural engineers in the team, Horner Foundations has become an established and trusted choice for underpinning services in Berkshire, Buckinghamshire, Hampshire, Kent, Surrey and Sussex. Operating out of Farnham, we are well placed to offer a timely, responsive service that begins with an initial visit to your site, a detailed survey, an investigation of soil conditions and a written quotation.
We then make calculations to determine the best method of underpinning. Horner Foundations also specialises in mini piling and basement construction.