The underpinning to cottage requirement is: cottage has subsidence to the front elevation. The likely cause is inadequate foundations when it was originally constructed along with the fact that it is in a elevated position with trees in the vicinity. The subsidence is easily identified by the structural cracking to the brickwork externally and cracking to the internal walls.
The front corners of the property are where the building subsidence is most prevalent. This is because of where the greatest load is being imposed on the foundations from the property.
The way to rectify this building subsidence is by traditional mass concrete underpinning. The depth the traditional mass concrete underpinning will be determined by the load of the building and the ground conditions. The structural engineer’s underpinning design will specify this and be calculated by a site investigation report or trial holes.
Typically, if the traditional mass concrete underpinning is over 1.5m in depth the structural engineer will design it with reinforcing. The strength of the concrete will also be calculated by the structural engineer.
Building subsidence often occurs during the summer months when the ground dries out and shrinks leaving voids which the building can subside into. Large trees in the vicinity accurate this process as they remove a lot of moisture from the ground in their vicinity and depending on the specimen can develop a large root system.
Where tree roots have grown under a building, simply felling the tree will not always solve the situation and the building may still suffer subsidence and require underpinning. This is because as the roots rot and decay they leave voids in the ground that the building can sink into.
Because of the wide variety of reasons that can cause building subsidence and the need for traditional mass underpinning, it is essential to get a professional structural engineer to identify the cause of the problem. Only then can a professional remedial underpinning scheme be designed to correctly address the issues of building subsidence within the property.
At Structural Repairs we have a wealth of experience of dealing with properties that have suffered from building subsidence and require underpinning especially underpinning to cottage, so contact us today to discuss the best way forward.