It is a method of foundation masonry repairs that stabilizes and strengthens foundations. In most cases, foundation underpinning repairs differential settlement. The foundation may sink into the ground in an uneven manner. Differential settlement places a large amount of strain on the foundation, and may cause severe structural damage. This is done by raising that portion of the foundation.
What are the causes of differential settlement?
Different factors can affect the settlement of claims, for example:
“Expansive Soil” – Because expansive soil contains clay in high proportions, it expands and shrinks with water. This can create movement beneath your home and over time lead to differential settlement.
It is important to avoid soils that are prone of erosion. They can be washed away by rain and cause voids underneath the foundation. When the foundation settles into these voids you will have differential settlement.
-Thirsty trees roots – Tree roots searching for water will “drink” moisture out of the soil, leaving voids behind.
If the soil is not compacted properly, it will settle into the ground after construction. The structure can settle after being built if this step is not performed correctly.
When the soil in the upper part of a steep hill moves downwards, it is known as “downhill creep”. This may cause structural damage and uneven settlement to a foundation.
-Natural Disasters – Floods, earthquakes or hurricanes. Sinkholes etc. can also cause differential settlement.
Excavation close to the house foundation. This could result in foundation settlement and even destabilization.
The foundation can be damaged by improper drainage. If this is your situation, ensuring that you install the proper drainage system around your property will assist with any foundation issues.
Why does a foundation require underpinning?
As was just stated, differential settlement is one of the most important reasons for foundation underpinning. This isn’t always the case. Additions, renovations, and adding stories to the building are all reasons to consider underpinning a foundation.
The foundation of your house will be stabilized and lifted for many decades by lifting the foundation, stabilizing its level and installing piers.
How are underpinnings done?
Two of the most popular methods to support a structure are helical or push piers. Which method is selected depends on several factors. These include the weight of the structure, the state of the foundation and more. To install push piers, the weight of a building is driven into the ground and the soil to be loaded. Helical piers can be screwed under the house, then installed, tracked, and recorded. As soon as all the piers meet the required depth and capacities, brackets are attached to the base and then the helical foundation is installed. Then the load is transported onto the system. Helical foundation piers may also be needed for new construction, house additions or in certain cases, porches. These helical foundation piers allow the new concrete to rest on a solid base and will prevent any clay and weak soil from affecting it.
Push Piers generally require the following installation procedure:
First, it is necessary to excavate down the footing of the affected area.
These brackets will support the piers. These brackets hold the piers.
The structure is pushed down into the soil using hydraulics and weight.
When the piers or pillars are placed, they attach to the steel brackets. An automatic hydraulic lifting system is then used to lift the building as high as possible. The structure is elevated as far as possible while avoiding damage.
Once the repairs are complete, it is necessary to replace all of the removed soil.