Foundation of your house or building is an important aspect that determines its durability. However, with time, the foundation starts deteriorating, or the soil beneath the foundation starts becoming loose.
This is when foundation underpinning comes to the rescue. This process helps you in strengthening the foundation of your house, and thus helps you in boosting the lifespan of your building.
Underpinning is a method which has become very popular these days and is used to mend and strengthen the foundation of any building. One can also get his/her house raised by a few feet in order to get protection from hurricane or flood. Underpinning not only helps to strengthen the foundation of a building but is also useful in making a new foundation for any building.
At times, after the entire building is completely built, some flaws appear in the foundation. In such cases it is important to retain the stability of the structure and underpinning comes to play at this time.
The underpinning helps to strengthen the foundation of not only the new but the old buildings as well. In simple words, the entire process involves three basic steps-
- Digging the ground at a required depth
- Installation of permanent or temporary support to the pre-existing foundation of the infrastructure
- The bearing capacity is gained, and the structure gets a new foundation
When is Foundation Underpinning Used?
When any structure is to be shifted to the other or new foundation which is stronger or the house has to be raised to a few feet.
Underpinning is also useful for structures whose foundation is not stable and the soil is not strong enough to hold it for a longer period of time. It is useful in cases where the soil foundation is to be stabilized in order to protect the house form natural calamities.
This method is very useful in cases where mistakes were made during the construction of the initial foundation of the building.
Methods of Underpinning
There are various methods and tools used to do the foundation Underpinning. Some of them are:
- Mass concrete Underpinning method which is also known as pit method.
- Mini-piled method
- Helical pile method
- Pier and beam Underpinning method, etc.
Out of all the methods, Helical pile and helical bracket method is used in abundance for foundation Underpinning.
What is the Helical Pile and Helical Bracket Foundation Underpinning Method?
Helical piles and helical bracket methods used for foundation Underpinning is the best method as it stabilizes the foundation for a longer period of time. Helical pile method mainly involves extending the foundation either in depth or width in order to acquire the desired results. This way the foundation rest on a better stratum of soil and the load of the structure gets distributed over a larger surface area.
Let’s have a quick look at the process involved:
- The digging is done in and around pre-existing foundation in order to extend it in width or depth. The concerned structure is also raised at the required height, say about 2 feet.
- Then, with the help of steel bracketing system, the helical piles (which come in various shapes and sizes), are attached to the foundation. For this purpose, engineered eccentric brackets are best to use for any structure or building.
- These brackets are then placed along the side of the foundation. Then, the main process begins where the load of the foundation is transferred to the pile members.
- There is one more way to carry out this method. In this process, the brackets are directly installed under the foundation and these brackets are in line with the helical piles which are installed.
- Finally, Underpinning brackets are adjusted on the marked spots.
The entire work can take up to 2-4 days. Make sure to hire the best team of engineers to do this work as the precisions involved during the process has to be to the point.