What is Underpinning?
Underpinning is a method of deepening and repairing existing foundations which have lost their strength or that need to be altered because for other reasons. There can be several reasons for this loss of strength. The soil quality may have changed over time. Its load-bearing value may have been affected because of climatic conditions. The soil may have suffered contamination. In such cases, the foundations can no longer be considered reliable because they can shift and even break down.
Underpinning can also be used if natural hazards or construction of nearby structures have damaged or undermined the existing foundations. Several types of underpinning techniques are used for resolving these issues. Two of the most common methods are mass concrete and cantilever needle beam underpinning. Our expert construction team specialises in providing underpinning services. Get in touch with us today to learn more.
We can provide:
- A free quotation and professional advice
- Mini piling to combat the effects of subsidence
- High-quality work, guaranteed
- A prompt solution using special piling machinery
- Greater stability your foundations and walls
- A safe and fast-acting service that minimises risk
Traditional mass fill underpinning.
Traditional Underpinning Mass Fill The traditional method of underpinning is where the affected structure has sections excavated in a “hit and miss” sequence to a pre-determined depth below the existing foundation.This is then inspected by local building control and each excavated pit is then filled with concrete Pile and Needle Beam Underpinning Mini-piles are installed to either side of the affected wall, a pocket of brickwork is then removed below ground level then a pre fabricated steel cage is installed to span over the two piles. This is then inspected by local building control and then concreted. This requires access to both sides of the wall
Piled needle beam
Piled needle beam techniques are ideal when solid ground is considerably deeper, therefore the traditional method is not applicable. A pre determined number of piles designed by a structural engineer will be installed within a shallow trench. Within the trench steel reinforcement will be added and concrete. All will sit firmly under the failed foundations.