How Does Underpinning Work?

“Underpinning” refers to the process of strengthening an existing foundation to increase load-bearing capacities. It is often used to restore old buildings, pop-top renovations (add a new floor to a home), and condo conversion (subdividing the property into multiple units which require additional load-bearing – such as multiple bathrooms or kitchens). You should consider underpinning if there are cracks in the foundation or plans for a taller structure.

An underpinning procedure is used for building and finishing a basement within the existing building. Underpinning involves the deepening of an existing foundation (resting upon poor strata) and putting it on deeper soil strata with higher bearing capacities. It is a method to strengthen a solid foundation.

This method which is traditional is mass concrete underpinning. This technique involves digging a section below the foundation of a building in controlled stages. At the depth where suitable bearing strata. This method is suitable for shallow depth underpinning and is very cost-effective.

 A foundation underpinning is a process to increase strength and structural integrity . An expert can place an underpinning structure underneath your home. This will give your foundation additional stability.

Image is of an underpinning in Adelaide by our team Adelaide Underpinning Group

Many cases of concrete underpinning involve unstable or defective foundations. Such foundations are usually caused by the age or changes in the ground around or below the existing structure.

Underpinning will also be required in the renovation and rehabilitation industry, as investors are planning to add more floors to the property. The foundation must support additional weight if you plan on adding a third or fourth floor to a two-story property. This is possible because the foundation and above-ground structures are protected by the underpinning process.

There are many ways to underpin. How ever, not all methods require structural engineers.

The “pit method”, which is also known by the name of concrete underpinning and has been used for over a century, is the most common. This method employs hand-dug holes that are placed 8-12 feet apart under the existing foundation and then filled with concrete. This method is very popular due to its simplicity of engineering and low-cost labor.

Beam and foundation underpinning (also known as beam and base) is a more complicated method. It involves embedding a concrete beam made from cast concrete. The beam is reinforced which extends to concrete piles beneath the beam. This spreads the load-bearing strain across multiple points.

Why Underpinning is Important?

Underpinning can be important when the foundation of a property has been compromised and is no longer able to bear an additional load. Underpinning is used in both these cases to repair the damage and maintain the property’s structural integrity. Without underpinning, the structure could quickly collapse, causing more damage than underpinning.

No matter if your foundation is damaged from earthquakes or erosion, or if you just want to increase the property’s weight, it is important to have an experienced structural engineer consult you before underpinning. Make sure you choose a contractor who has worked with underpinning. We can provide you with financing as well as guidance during your renovation project.

Know The Importance Of Underpinning

 Underpinning refers to strengthening and reinforcing a foundation for a structure. It is usually done by increasing the depth and breadth. There are many reasons why underpinning is necessary. Below is a list to help you understand the unique utility of underpinning.

If a structure requires underpinning then it is due to the following reasons: 

  • The original foundation isn’t strong/stable enough for the current structure.
  • It was not the original purpose of the structure. Therefore, foundation reinforcement is required.
  • The soil cannot support the weight of the structure.
  • A second story is being added. This will require deeper foundational feet to support greater load-bearing capacities.
  • It’s cheaper to repair/reinforce rather than to buy new one.
  • Structure’s security has been compromised by earthquakes, droughts, floods, and other acts of God

A simple way to think about underpinning is this: any outside force that compromises the strength, integrity, and functionality of your foundation/footing is a reason to underpin (provide reinforcement/structural support).

Underpinning in construction is the process of strengthening and stabilizing a building’s foundation. If it wasn’t done, it could prove to be dangerous. What are the advantages of underpinning a structure or building? These are some of the questions you might ask if you’re told by a supervisor that your building requires underpinning. 

Following are some of the advantages and reasons one should think about: 

1) Existing foundations are weak or unstable. Underpinning will fix these issues.

2) The building’s use has changed like the owner has changed its purpose.

3) The soil properties on which the building is built have changed – it could have been affected by subsidence or movement of the ground. Underpinning will strengthen the structure in such cases.

4) Addition of new buildings or structures to the area. A new house built next to an existing home may require underpinning to help strengthen it.

  • The land cost has risen. If land prices rise significantly, it may be cheaper to use underpinning to improve the property (perhaps adding another floor) than to purchase more land.

To get the best underpinning companies near the locality then you just need to search on Google “Underpinning companies near me”. Then you will the best companies near your house.

Types underpinning

 There are three primary types of underpinnings: 

1. Mass Concrete Underpinning/Mass Pour- Mass concrete underpinning might be the oldest and most commonly used foundation repair technique on the planet. This involves digging holes or voids below a weak foundation and pouring new cement/mud/filler beneath the original foundation. This provides extra support and depth to the foundation.

2. Beam and Base Underpinning-This is a modern type of underpinning, where a reinforced concrete/steel beam is constructed below, above or in replacement to the existing footing. The beam then transfers the building’s mass to the concrete/metal base, which is strategically placed at load-bearing places.

This is slightly less sophisticated than mass concrete underneath pinning, in that it is adding concrete/steel to an older concrete/steel base and not replacing it.

3. Mini-piled Underpinning- This type allows for the maximum flexibility regarding where access is restricted/restricted, and how significant environmental pollution is. Mini-piled underpinning refers to situations when the structure’s loads need to be transferred to more load-bearing soil at greater depths (occasionally up to 50 feet).