I’ve encountered major water after auguring down about 4′ ( our code ) to set posts for beams that will eventually have a small out building built on top. ( much like you would a deck ). A concrete slab is not feasible in this location and this seamed like the next best thing. My concern is getting around the water that flows up about two thirds of my hole. The area was a swampy forest back in the day with mostly soft clay for soil. Is there a certain concrete mix that will cure in the water? should i drill deeper? Bigger than 8″ for 4X4’s? The building will be garden shed/shop 12×16 so i don’t need an over kill solution…any ideas out there?
Thanks all!
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You can pour concrete under water, you don't need a special mix. Many of us avoid putting wood in concrete, even PT. Contact with concrete or earth shortens life. I would use sona tubes and keep the tops a couple of inches above the ground level, use a post anchor and go from there.
Beat it to fit / Paint it to match
I have run into this a couple of times. I got bags of Redicrete ( premix concrete / sand/aggrigate , Post Hast is another brand) and place in hole around the posts, tamp and keep pouring in till water /mix comes to top, brace posts and let sit till cured. You just use the water that is there for the concrete, or just place a real dry concrete mix into the hole.
IF IT WAS EASY, EVERYONE COULD DO IT!
you can pour under water as was mentioned... use a large sonotube and pull it up as you go so the concrete is displacing the water instead of mixing with it
what you really have to be careful of is making sure you have good bearing soil at the bottom of the hole
if this is an old swampy area the peat should be pretty deep
your auger has to go thru all the unsuitable soil or the footings will sink instead of bearMike Hussein Smith Rhode Island : Design / Build / Repair / Restore