The typical way of doing a concrete patio floor is to excavate soil at least 9", pour & compact gravel, then pour concrete.
I was wondering, what will happen if:
- Excavate post holes, past the frost line, in each corner of the planned concrete floor.
- Set rebars vertically in the holes
- Add horizontal rebars "connecting" the posts rebars.
- Add some more rebars, forming a "mesh"
- Set the concrete form (2×4's)
- Pour concrete, level and seal.
Basically, a concrete slab sitting on top of soil, with post foundations.
Will the concrete floor shift in level in no time? Will the ground crack and break it sooner than later? I live in Canada (Southern Ontario) where the ground goes through a freezing cycle.
Best Answer
As long as the total contact area of the footings in consideration of the load bearing capacity of your soil exceeds the total dead & live load of the patio, then it won't settle into the ground.
As long as the footings are below the frost line, they themselves will not frost heave.
However - if the slab is still in contact with the ground, then it will still be susceptible to frost heave. The entire contact area of the slab with the ground - except the footings - will be above the frost line and can get damaged.