I would appreciate anyone’s insight into this situation:
The excavator dug out the pit for my 24′ x 24′ addition. He dug a beautiful hole to 30″ below grade. To our surprise, the water table was right there too, at 30″ below grade. To dry out the hole, I hand dug a 12″ deep trench around the very perimeter of the pit and installed a 4″ filter-wrapped drain tile, covered it up with drain rock, and trenched it out to daylight. The water flowed rapidly for a couple days, and then steadily. Test pits I dug in the bottom of the pit reveal that between 8″ and 13″ below the 30″-below-grade-bottom-of-the-pit level there is a clay layer that the water table seem to sit on.
THIS IS MY QUESTION: Should I let the bottom of the pit dry out thoroughly and then pour my footings on the dry soil?, or should I dig out below where the footings will be down as deep as the clay layer and fill that area up with compacted gravel and then pour my footings on the compacted gravel.
Thanks for your insights, Billllll
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Greetings billllll,
That's an interesting dilemma.
This post, in response to your question, will bump the thread through the 'recent discussion' listing again.
Perhaps it will catch someone's attention that can help you with advice.
Cheers
half of good living is staying out of bad situations
compacted gravel
I'll second that normally but I'd like to know what the existing house is setting on first
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The existing house foundation is resting at 30" below grade on the less-than-drained-dry soil. There is a crack in the foundation wall near that corner as well as cracks in the sheetrock in the corner room.
Billllll
That 8" - 13" layer on top of the clay.... what is it? Topsoil?
It is a damp sub-soil. Below it is this definite hardpan where the water doesn't easily pass.