Toronto Underpinning & Basement Lowering

Underpinning the foundation walls: In this method, a staged sequence of holes are dug-out from under the footing of your home. (The footing is the concrete or brick pad which spreads the load of the foundation walls onto the soil.) Typically, a 3′ wide holes, separated by at least 6′ of undisturbed soil, is prepared and filled with concrete. Once the first stage of underpinning segments are complete, then the adjacent 3′ wide segments are dug-out, and the underpinning process is repeated. Here, the idea is that you first extend the footing of the house to a lower level, after which you can safely dig-out the soil from the inside of the basement, without undermining the foundation walls of the house.


Benching: In this method, a stable soil slope usually not exceeding 7V:10H is maintained between the sub-grade under the lowered basement floor level, and the underside of the original footings (to avoid undermining the footings). Then, a steel reinforced concrete “bench” is poured over top of the stable soil slope and footing, to ensure that the soil slope is protected. This process is less expensive than underpinning, however it leaves you with a concrete bench around the interior perimeter of the basement, which will decrease the square footage of your basement.