Foundation settlement can generate important disorders to a building, which may lead to its devaluation. Experts highly recommend by to stabilize foundation by using piers. Underpinning or « piering » foundation is a technique which consists in driving steel pipes (either helical or standard « push » piers) to bedrock or into a suitable soil bearing layer. The piers are disposed at regular intervals so that the weight of the building is distributed evenly over along the foundation walls. The capacity of each pier is then load tested before being anchored to the building and filled with concrete.
This solution offers stability and sustainability to the building for its life. It is also the only solution that prevents foundation settlement. It is also much more economic than replacing the whole foundation.
Standard push pier
Standard push pier is a steel pipe driven to the rock by using an hydraulic ram. This type of pier offers a higher weight lifting capacity and sustainability rather than an helical pier.
Depending on the conditions, disposition and strains on the building, it is possible to level back the building. Once the piers reach the bedrock, lifting hydraulic cylinders are used to jack the subsided parts. Buildings attached with common walls and rock rubble foundations cannot be lifted. This technique is usually used on houses.
Partial stabilised foundation
In cases of a partial foundation settlement, experts might propose to stabilize only certain walls of the building. However, even if it is more economical rather than stabilizing the whole foundation, this solution doesn’t prevent the other walls from sinking in the future. This is usually the first step of stabilizing the whole foundation.