If you've outgrown your current home and want to add additional space to keep your family happy, you may consider building an extension. While you may be working on the design and configuration, you also have to pay close attention to the foundations. In this case, it may be necessary to underpin the existing structure so that it is able to cope with extra forces. What do you need to know about this potential requirement?
Assessing The Current Foundations
If the original foundations of your primary structure are still in good condition and you have not had to deal with shifting soils or other issues, you may only need to underpin certain areas. This work can be localised to take into account the fact that some of the load from the new extension may permeate to the rest of the building. Builders may need to form part of the new concrete foundation partly beneath the existing house footing at what is known as an "abutment" point.
Performing An Engineering Analysis
Engineers will have to look at the plans carefully to see how much load may eventually impact the closest part of the structure. They may have to expose the primary foundations in that area and check to see if they are adequate. Often, this type of work will be down to a building inspector, but they may also consult with a structural engineer to get the full story. This engineer may look at the subsoil and the foundations in place to see if the setup is adequate. You may not need to strengthen the current foundations if the engineer finds they are capable of withstanding the additional demand.
Working With Underpinning Contractors
If the structural engineer is unsure or there are clear indications of a deficit, you should bring in underpinning contractors. They will also work with engineers and builders to determine the new "pinch" points and ensure that concrete is pumped into these areas to stabilise the soil. They may also need to bring in separate screw pins that may be linked to existing concrete or wooden pins to form a latticework and provide plenty of support.
Finding Out Where You Are
So, you will first need to bring in experts to determine exactly what you're dealing with. You may not automatically need underpinning services, but you will certainly want to be aware of the situation so you can plan and budget accordingly. For more information on residential underpinning, contact a company near you.