Every builder knows that conventional footings must be placed lower than the deepest expected frost depth. For a garage slab, my area’s 42-in. frost depth usually means deeply excavating perimeter trenches, pouring concrete footings, and building concrete or CMU-block stemwalls atop the footings. Then backfill the stemwalls, add a layer of gravel and a plastic vapor barrier, and then pour a 4-in.-thick concrete slab. There had to be a better way.
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Im am no concrete pro but not a fan of sheathing and siding touching ground especially here in Canada where the winter -30C will leave 3 feet of snow and ice resting on the base plates for a long season and the garage our house will be heated , unless laying concrete blocks all around who become pointless at this stage !
I'd like to know how the author slopes the slab 1/8" per one foot when it's a monolithic slab? And he excavates down 1 ft for the edge. Does that mean the framing, sheathing and siding is at the grade level? Doesn't all wood need to be 8" above grade? Thanks for any help with this. I like this idea in concept.