What Foundation Underpinning Is and Why You Need It


There are a few things that might cause a foundation to fail. Acidic water from wells or marshy areas, for example, can easily eat away at the cement and brick. And because the only thing holding up your home is a concrete slab with no outer wall, improper drainage can also be a major issue. That’s why you may need a foundation underpinning. Basically—things have to be done right the first time!

Luckily for us, there are engineers and contractors who specialize in foundation underpinning services; experts who will ensure your home’s long-term structural integrity by installing steel rods beneath your concrete slab using drilling equipment. This is a job that needs to be done correctly the first time — any damages will likely have to be repaired again at a later date.

What foundation underpinning is?

Foundation underpinning is a procedure that is used to reinforce (or underpin) an existing foundation wall. This can be done in a variety of ways, but it usually involves drilling anchor holes into the foundation wall and then inserting steel rods with high-strength connectors into these holes. These connectors are placed at various locations along the length of the foundation wall, and when pulled tight, they add lateral support to that wall.

There are several types of foundations: Underpinning may not work for every type. For example; if you have a crawl space or full basement, there’s usually no structural issue to begin with. 

Types of foundations

Foundation support can be used where there is a possibility of movement caused by the ground underneath. This could be due to poorly built footings or poor grade subsoil, or even soil settling that happens with weather changes. Foundation support has become more popular since the early 1900s, when a foundation was often just a simple slab of concrete on top of a wooden subfloor. Once you add steel rods to the foundation, you also get better water drainage and additional strength.

5 main types of foundations are:

  • Wood foundations;
  • Pier and beam foundations;
  • Concrete slab foundations;
  • Basement foundations;
  • Crawlspace stem walls. 

Underpinning for basement foundations is a fairly easy process for experienced home owners. It is important that the structural integrity of your basement be kept intact by having an expert inspect it to determine if the entire basement should be excavated. If excavation is found to be necessary, further inspection must then take place with experts in order to determine what type of slab should be installed. And after the work is done you may need the help of a professional landscaping contractor.

Why use foundation underpinning?

Firstly, because of the very nature of what it is, and what it is used for, the foundation underpinning process is one that needs to be performed with care. This is because of the stresses exerted on any structure that has been built on top of a weak wall. It’s therefore essential to have a professional do this work; trained in how to install this and know how to properly do it.

What they’re really saying here is that if you decide to go with foundation underpinning — where an experienced professional will drill anchors into your wall and then place steel rods in place — do so only after getting an estimate from a certified contractor. This will help ensure the job is done right, so you don’t have to call back and redo or waste money.

Underpinning can also be an option if you’re experiencing settlement issues in your basement. But before you go and assume that everything is fine down there, make sure to look into the other options where this could be a problem.

Bottom line

Underpinning is a process that should be considered by anyone who has had any significant issues with their foundation, inside or outside. The purpose of foundation underpinning is to reinforce the existing concrete slab and provide additional support for the foundation. Foundation underpinning is a very important part of any construction project, and it should not be overlooked even if you think your home should not require this kind of work.