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Underpinning

Underpinning is used to reinforce settling foundations. But is it the best option for you?

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Without a stable foundation, there is no stable home. Unfortunately, a lot of homeowners don’t remember to check their foundation during their annual home maintenance. While problems such as a leaking roof, drafty windows, broken faucets, or clogged gutters are rather obvious and catch our attention quite quickly, foundation issues can be hidden and tough to spot, where they only grow as time passes. What is even worse, foundation problems lead to a wide variety of other issues. For example, cracks in foundation walls can lead to a mice invasion or invite termites into your home. Moisture that enters your home can cause mold growth and even increase your electric bill because your heating and cooling systems need to operate much longer than usual. In addition, problems with your foundation can cause plumbing pipes to break and flood your home. 

So, how does something that is mostly underground get so damaged? Foundation problems occur for several reasons, but one of the most common ones is changes in the soil. If the soil underneath your home shifts or becomes unstable, your home will need to be reinforced, or otherwise, your foundation will crack or suffer from settlement. Luckily, with underpinning, the foundation can become stable once again, and able to bear the load of your home. If you haven’t heard about underpinning, keep reading. We will explain what this process entails and when it is a good option.   

underpinning foundation

What Is Underpinning? 

Underpinning is the process used to repair or strengthen an existing house or a building. When contractors begin with underpinning, first they dig out the soil underneath the foundation. However, the excavated soils are not moved all at once, but in stages so it doesn’t come to structural problems. The whole process should be completed by professionals since even the tiniest miscalculations can result in disaster. Structural engineers need to calculate how much soil should be excavated until stable soil is finally reached. During the underpinning process, one layer of soil will be removed, replaced with an underpinning material, and only then the next layer will be removed. This process is repeated several times until stability is achieved. 

Reasons for Underpinning 

When the usage of the structure has changed, sometimes the foundation needs to be reinforced, which requires an underpinning process. Sometimes the need for this process rises due to the changing properties of the soil supporting the foundation. There are times when the stability of the soil was mischaracterized during the construction of the structure, so now the homeowners need to strengthen the settling foundation. In addition, if owners of the house wish to expand their home and add another story, they need to reinforce the foundation first, otherwise, the structural stability of the entire house could be compromised. Another reason for underpinning is changes in the soil caused by a natural disaster such as an earthquake. 

Types of Underpinning 

Sometimes, reinforcing the foundation is a necessity. When it comes to the underpinning process, there are various types builders use these days. One of the most reliable is the pile or pier method. If your home in Michigan currently sits on unstable soils but there is better soil a layer below, albeit at a significant depth, the pile method is recommended. During this process, the foundation piers are evenly distributed along the foundation. Their purpose is to lift it and transfer the load from the foundation to the piers. 

Temporary Underpinning Solutions 

If there aren’t any significant issues with your foundation, your contractor might recommend some of the temporary underpinning solutions. Keep in mind that these are not permanent solutions. 

Concrete underpinning: With concrete underpinning, the soil underneath the foundation will be excavated and a new layer of concrete will be poured under the existing footings. The idea behind the process is to lower the footing so it can stand on more supportive soil. After the concrete has dried, the left gaps will be filled with the excavated soil. However, this method doesn’t exactly address the unstable soil. 

Concrete piers: Concrete piers are concrete cylinders connected with a wire. They are driven into the soil, but since nothing is guiding them, they cannot go deep into the ground, which might be a problem. 

Durable Underpinning Solutions 

Fixing your problem for good is always a better option, and this way you will be at ease knowing that your foundation has been properly reinforced. Here are several foundation pier methods that can be used to strengthen your foundation and ensure the stability of your home. 

  • Push piers: One of the most popular types of piers is push piers. These are driven into the ground and their main purpose is to permanently stabilize the foundation. They also can potentially lift it back towards its original position. They are made from galvanized steel, so you don’t have to worry about them rusting over time due to the moisture in the ground. 
  • Helical piers: Helical piers are similar to push piers, except they are screwed into the ground instead of being driven into the ground. They are ideal for lighter structures like porches and chimneys. 
  • Slab piers: Slab piers are designed to support a slab foundation and prevent it from settling. 

If you have a problem with the settling foundation, contact professionals at FSM to schedule a free inspection and repair estimate. Our inspector can assess the situation and recommend the best way to reinforce your foundation. 

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