Slab on Grade Foundation With No Grade Beam or Footing
I am hoping someone can answer a question I have regarding an existing slab on grade foundation that I would like to build on.
It is a roughly 20′ x 18′, 6″thick slab that was poured next to an old detached garage that I am currently remodeling. I don’t know when it was poured because I just purchased the home a little over a year ago, but it is level and square, and appears to be in good condition. It currently supports a lean to that spans the length and width of the slab. I would like to tear this down and build a fully enclosed, single-story addition in its place.
The issue is that there is no grade beam or footing for the slab. It is just a solid 6″ thickness all the way around. My question: Is there a way to dig around the perimeter and pour a grade beam or footings underneath the slab without destabilizing it? If that is not an option, would I able to dig adjacent to the perimeter and pour a stem wall around the slab? And if neither of those are possible, is there another solution that anyone might have to offer?
Thank you!
Replies
This might help you. These are standard plans for Virginia. https://www.fairfaxcounty.gov/landdevelopment/sites/landdevelopment/files/assets/documents/pdf/publications/carport_details.pdf
Thank you!
It all depends on the frost depth, How deep you have to go, and what you find when you dig.
it would seem easier to dig along the perimeter and make the outside of the slab the inside of your new foundation.
Thank you!