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Toronto Underpinning & Basement Lowering

If you are looking to add extra space to your home by lowering your basement , the Addison construction team can provide you with a free on Site Consultation and then prepare the building permit drawings that you may need for your project.

What is Underpinning?

Foundation underpinning is a repair process that strengthens foundations that have been weakened though a variety of factors. In the process of underpinning, the area underneath the load of the foundation is repaired or reinforced for a safer, more stable base.


Underpinning Methods

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.

Underpinning Time Line & Construction 

The underpinning of a basement can be completed between 4-8 weeks. However our team will have to conduct a site visit in order to understand the exact scope of the projects circumstances , as sometimes there can be an unforeseen issue along the way especially for older houses.

Contact Us

Ready to start your home renovation project? Fill out the form to request a free in-home consultation with one of our experienced project managers. We'll work with you to create a customized plan that fits your unique needs and budget.

455 Danforth Avenue, Unit 425
Toronto, ON
M4K 1P1

Thank You For Contacting Addison Construction

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