If you are thinking about building an extension to your home, you need to ensure that the current structure is capable of withstanding the additional load. Sometimes it may be able to, given its present configuration, but at other times you will need to carry out some strengthening work before you can proceed. What do you need to know about this activity, known in the industry as "underpinning"?
Improving the Status Quo
When your home was originally built, it would have been designed to cope with the expected loads and take into account the engineering techniques of the day. While many builders of that day would have stayed on the safe side and put extra effort into the foundations, they would not have been able to anticipate a significant extension. Consequently, it's quite likely that you will need to strengthen your foundation before you can risk adding extra weight, and you need to get permission from the local authority regulators anyway, who will also look at this matter carefully.
Mass Concrete Injection
While there are different procedures involved with underpinning, the most commonplace in this situation will involve mass concrete. Engineers will need to excavate small sections of the ground at a time beneath the existing foundations. They will then bore down to a specified depth until they find suitable soil conditions. They will then need to bring in a local council inspector and get their approval before they can begin the process of pouring the concrete.
The contractor will slowly but surely fill each open pit with concrete before waiting for it to cure and set. Before they move on to the adjacent section and begin the process again, they may install a dry pack of mortar between the new and the old foundation to help safely transfer the load onto the new structure.
Attention to Detail
This may be quite time-consuming, and seasoned engineers will want to transfer the building's load with great care. After all, they won't want to compromise the strength of the existing building in any way as they try to get the overall structure ready for your new extension.
Working with Experts
While mass concrete underpinning is often a chosen approach in this situation, your engineers may advise something else. Make sure that you always talk with experienced technicians and, ideally, those who have worked on similar projects in your area. They may be familiar with the soil condition and the local council's requirements and can get the job finished as efficiently as possible.
Contact a company that offers underpinning services for more info.