What is the underpinning of a foundation? Underpinning reinforces the structural integrity of a building foundation. It is typically needed when the foundation is no longer strong enough to properly support its house. Generally speaking, this results from soil changes underneath the foundation -- including freezing and thawing, shifting, and poor soil breaking down. To fix this, soil may be strengthened with an expanding filler or by extending the foundation so that the load of the home ins distributed over a greater surface area. For information on foundation repair services in Akron, call our contractors today for a free consultation!