Oklahoma-Land of clay soil and high water table

Discussion in 'General Homesteading & Building' started by Iwatch, Nov 3, 2009.

  1. Iwatch

    Iwatch New Member

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    Hi everyone,

    New to the forums here, but it's what I've been looking for for some time. Glad to find some like-minded souls.

    However, I'm in a bit of a quandary. I'm looking to buy some land soon and build my own house on a shoestring budget, but I'm concerned because living in Oklahoma causes lots of problems when trying to build.

    I originally wanted to build a bermed house, but don't think it's maybe the best idea here because the clay soil just retains water and expands etc. Not to mention the high water table.

    I considered building a house out of cob (clay, straw, sand, gravel mix mushed up by your own feet and therefore darn cheap), but the water problem kind of steered me away from it. Cob doesn't do so well with constant wetness on it. Then I thought about rebar and concrete walls and floors, but then I worry that it will crack because of the soil expanding etc.

    To combat cracking concrete slab foundations, it seems that piering up your foundation is one of the best bets, using the steel ones that go really far down until the clay becomes less unstable - the concept is sort of push the foundation piers down until they meet enough resistance to keep steady while factoring in just how heavy your home will be.

    I also have been considering making a house of CEB (compressed earth blocks) which looks pretty viable with the abundance of clay in our soil here, but it is very heavy like cob and I'm not sure it withstand the wet so well either. But it looks like it would be another great cheap alternative for building.

    I've read that bermed houses tend to be humid and it's plenty humid here in the summers. But....I like the way they're hidden in hillsides and I am looking for a tornado proof house, which bermed housing affords. CEB also seems to be very good at keeping humidity around 50% and is very strong. So I am wondering if anyone knows if a CEB bermed house in humid Oklahoma would work or if anyone has some ideas of ways to build with these challenges.

    Any ideas would be much appreciated. Thank you and glad to meet you all once again. :D
     
    Last edited by a moderator: Nov 3, 2009
  2. NaeKid

    NaeKid YourAdministrator, eh?

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  3. heather7

    heather7 New Member

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    berm with cement blocks

    My brother built a storage room (semi underground) with cement blocks. Within a couple of months, everything was covered with fuzzy white mold. That happened despite the air vent in the roof. You don't see many basements or anything underground in eastern Oklahoma. Maybe thats why. The western part of the state might be dry enough though.
     
  4. longtime

    longtime Well-Known Member

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    I was waiting for someone in OK to make suggestions, mine might not be relevant.

    I live in Kansas, about six in. of top soil then clay down to rock. Water table is about 4 feet down.

    I have built a full basement and it is dry without any damage by the expansive clay.

    I dug down to the rock ledge, water running along the top of the ledge. I then ran a drain to daylight to drain the hole (a 300 ft trench was needed). I glued a water proof membrane to the basement wall, used fiber board as a protective layer to protect the membrane. I then placed drainage tiles at the bottom of the footing, inside and out and along the outside of the basement wall ( three total). The outside ones went to daylight and the inside one went to a sump pit.

    I then back filled the hole with 3/4" washed rock to within 24" of the surface and covered it with geo fabric. Then back filled the rest with top soil.

    My basement was designed for the forces of the clay, I have external knee walls or a corner every 20' with #5 rebar on 12" centers each way placed 3" from my inside wall in a 10 thick wall.

    My basement is dry and no cracks have opened up, YET. When it does, I still expect it to stay dry because of the membrane.

    This has worked for me, so if your building a berm house it should be easier, no 300 foot trench to drain the walls. I would still use a sump for under the floor. As with any basement, I did notice a lot of moisture (humidity) in the begining, but after a couple heating and cooling seasons, it went away (I assumed it was coming from the concrete).