How do I calculate how deep the foundation needs to be?
user-2069108
| Posted in Mechanicals on
I need to put in a foundation, but I am not sure how deep it needs to be. The frost could be about 3 feet deep. Since I am also considering the wide foundation and not the very deep style, I think I can go down a bit less than 3 feet, but I am not sure how to calculate it to ensure it will support the house and not be a problem with the frost.
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Replies
Steve - making the wall wider won't prevent frost heaving. Unless you are using a frost protected foundation, you need the footings and bottom of the wall below frost depth. Any contractor can tell you what the necessary depth is in your area.
Steve,
Requirements vary by location. Call your local building department.
This is just a guess, but if you don't know the required minimum depth for your footing, I'm wondering whether you are qualified to design your foundation or assess your local soils.