The method of foundation underpinning is a very common way to help improve an existing foundation. Underpinning takes the present foundation and extends it further downward into the ground where the soil is more stable and better able to support the foundation upright. There are several different ways to underpin a foundation. Some of them include drilled piers, driven piling, stem walls and footings.
The process of underpinning is most common in housing areas where the climate and the condition of the soil are more apt to have a negative effect on house's foundations; for example, areas with extreme variations in moisture levels such as rain or drought.
Underpinning can actually serve to elevate a house or structure up to a higher distance from the ground in order to put a stop to settling and provide better vertical support. If you are thinking about having your house's foundation underpinned, here are some things you will want to carefully consider.
Think twice before underpinning only a portion of your foundation. It is possible for areas that have not been underpinned to shift and move. For example, if a particular section under your house had sunk lower than the rest and was underpinned due to the settling, there would then be the possibility that a decline in moisture level of the soil below the house could cause the remaining portion of the house to shift downward when the soil shrinks.
This would cause the area that has been underpinned to now be higher than the rest because the underpinning would prevent it from settling as well. When this happens, there is a risk of foundational cracking between the underpinned section and the portion that is not.
There may be situations where partial underpinning is appropriate, but make sure it is the right thing for your foundation and not just an attempt to lower cost. There is too much risk involved to the investment of your home. Have a qualified foundation repair technician assess any possible risks before performing a partial underpinning.
Underpinning keeps a foundation from settling, or moving downward. It does not prevent it from upheaval, or moving upward. Anything that can cause the soil underneath the home to swell, such as massive rains, poor drainage systems, plumbing leaks, etc. may provide the basis for an upheaval of the foundation.
This in turn can cause floor instability, wall cracks and/or separation between walls and ceilings on the inside of the home. It is important to properly maintain moisture levels around the foundation of your home in order to help prevent upheaval and its consequences from occurring.
Remember, the process of underpinning requires a strong, stable connection between the foundation of the house and the piers that are installed to support it. If the proper link is not made between the two, the weight of the house will not shift over to the underpinning correctly and downward movement could still happen.
Underpinning is a common practice that can be very successful at supporting a house and foundation. However, it must be correctly installed and designed and proven to be the best solution for foundational support.