Underpinning is a very common procedure in most renovations of older homes with low basement ceilings. The idea behind it is to strengthen the existing foundation, while also increasing the height of the basement ceiling by excavating below the foundation walls and extending the footings lower into the ground. Underpinning is sometimes also done when unexplained cracks around the walls, windows, and doors are seen which are signs of foundation settlement. When the foundation continues to settle, more and more cracks will appear until the structural integrity of the house becomes compromised.
Underpinning is a process used to increase the depth of an existing foundation by lowering the footing so that it can rest on more supportive soil. But the way we put it: underpinning is simply the process of strengthening the foundation of a house or building and raise the ceiling height of a basement. Property owners need to make themselves familiar with this concept because the longer their houses stands, the more vulnerable it is to soil upheaval and settlement. When the worse of the problem manifests, cracks and leaks around the house and foundation will be apparent—hence the need for underpinning.
When the soil is already settled, voids underneath the foundation starts to form. This results in uneven stresses that can crack the concrete. ECC Construction Group Inc. recommends underpinning the house. Here’s a look on how we do underpinning: The first step that we do is we expose the foundation by excavating soil down to the footings to have a good look. This is typically done in very specific sections along the foundation wall according to the structural drawings stamped by the engineer. This is done for safety purposes to protect the house from collapse as it is being excavated from below. Once a section is exposed, rebar steel reinforcement is put into place so that the new concrete is strengthened and then concrete pre-mix is poured into the excavated section until it hardens with the existing foundation wall. This process is then repeated depending on how many sections the engineer has recommended, usually between 1 to 5 sections.