Underground Earth Bag

So the more I learn about WOFATI the more confused I get on how to keep it dry and rot free considering it's made out of wood and I live in the wet Ozarks. I am under the impression earth bag does not need tyvek or other plastic lining to prevent it from getting wet and it just needs a drainage pipe under the middle of the floor? the floor should have a layer of gravel with a drain in it and then I could put wood boards and rugs over that? The earth bag cellar builds I watched have logs and 2x4s for a roof then put bags over that and then plastic only over the top not over all the walls. Is this all that is needed to keep it a dry shelter? I am going to have three sides bermed up and the roof covered with soil with the front partially covered except for a couple doors or windows. Since tornadoes travel mostly from the south west or west, I will have my front be oriented north or north east. I hope that will help it keep cool in the summer and warmer in the winter. The front will eventually be attached to my future cabin/yurt/house whatever I can figure out.
I think I am going to make a 450 too 525 square foot underground storm shelter/root cellar/tiny home. My dream cabin is cordwood but that will not stand up to being underground.
Please help me figure out what I am missing and not understanding about how to build an earth berm earth bag temporary home/storm shelter/cellar. Videos are best because I can watch them with my kids so they can help me brainstorm and sketch out plans. I am basically building on my own and feel that anything needing a major beam/timer frame would be too big and heavy for me to handle on my own strength. My kids will be helping but they are not super strong either.

An underground house in a wet area is not going to be a house.
In my experience you will have moisture problems all the time.
If you could build it in a rise, where the low point of the structure can freely drain away, you may be ok.

Hi Gail,   I know the partially buried earth bag dome I helped make leaks a bit through the walls. I remember putting a layer of vapour barrier plastic on the outside before back-filling too.

Have you seen Kelly Hart's website? Loaded with very useful tips:  Earthbag building FAQ

I'm with John in that I'm sure anything is possible in all locations but always best to choose the best and driest possible location so your not working against nature.

I added your thread to the "wofati and earth berm"  and "ozarks" forums as well for more exposure if that's OK with you?

Hi Gail,

Here's a good starting page for a wofati i.  If done correctly, you won't have moisture coming thru the walls.  If done incorrectly, everything the above two posters have listed will happen.

Using both the lay of the land and two moisture underground umbrellas, all of the earth and wood will dry out and remain dry.

The small backhoe suggested to you in another post is definitely going to be needed.....the largest, most powerful one, with the largest buckets that can go across your bridge is best.

I think it depends on how much moisture rises up through the soil in your building site.  If you put up a "standard" house with a basement and then a year later, dig a hole through the basement floor, would it be wet or dry.  If wet, I think that the double umbrella plan may not work.  It keeps water from sinking through the soil and coming at your structure from the sides.  But if you have moisture coming up or a high water table, I doubt the umbrella can fix it.

I'm just guessing on all of this but that's how it feels to me.  I don't think a wofati with a 80' radius umbrella would protect posts in my area due to a highish water table.  Keep in mind that the wofati isn't really below grade at all.  But the posts are which is where my concern arises.

I hadn't thought of an earth bag wofati-style house but that could interesting.  In a wofati, the pole structure of the posts keeps the walls from pushing in.  With an earth bag I'm guessing you'd want to do a circular building (or series of circles).  The issue would be how you make huge openings for the uphill and downhill sides without the remaining half circles collapsing together.  A huge picture frame around the opening could be the trick.

Gerry Parent wrote:Hi Gail,   I know the partially buried earth bag dome I helped make leaks a bit through the walls. I remember putting a layer of vapour barrier plastic on the outside before back-filling too.

Have you seen Kelly Hart's website? Loaded with very useful tips:  Earthbag building FAQ

I'm with John in that I'm sure anything is possible in all locations but always best to choose the best and driest possible location so your not working against nature.

I added your thread to the "wofati and earth berm"  and "ozarks" forums as well for more exposure if that's OK with you?

Thank you for adding it to other forums. I hope to learn a lot here as I make progress towards starting some type of structure.

I need to borrow someones brain please! Mine is getting a headache trying to figure out what I want to do. If anyone with earthbag experience is in the Ozarks I would love to borrow you!
How big of a ditch/trench/hole do I need to dig to have enough clay soil to fill my earthbags AND berm three and a half sides of it? Is there like a ratio or something like for every hundred square feet you need one foot of cleared soil for the bags and one foot for the berm?
Would it be cheaper to actually buy dirt than pay an excavator? But wouldn't that kind of defeat the purpose of building with onsite materials? Also the rubble trench is just under the bags, not the entire square footage right? What goes under the actual floor? I was thinking it was gravel then a moisture barrier then a subfloor, but now I'm confused.
I have some supplies on the way but am not sure what my blueprint will look like yet! The more I think the more overwhelmed I become.
We could get buy with 250 or 300 square feet underground then build another 'room' in front of the buttress that would not be a storm shelter. I am actually thinking this is what I want to do to get a small but suitable root cellar/storm shelter in place sooner.
I have ordered 2000 14x26 bags, a tamper (if I can find a person to help build I will get another), two rolls of barbed wire, nails, polynetting bird netting, six inch staples, and .6 mil moisture barrier.  I think I got everything from the supplies list except for spider lathe. On the side I am going to berm, do I not need the spider lathe, is that only for where it will be mortared? What am I missing?
Even if we have to dig each part of the trench by hand and fill the bags by hand my kids are so terrified of tornadoes that we will find a way to get a basic storm shelter up, I just need to make sure I'm doing the right thing and all our effort will result in a safe, dry, secure shelter.

Hi Gail,

I’m interested in moving from KC to probably SW-SE Missouri in another year or two, paying bills off and stuff to fix on our house still for now. I was curious what the lay of your land is... maybe I missed it, but are you in lowlands, on a hillside, plateau...? I only want to look at hillsides/sloped land for a house spot, personally. I know Mike Oehler discusses underground for flat land, but not interested here. I’d recommend his books and even more, his videos. Paul has a deal on here to get both the underground house book and greenhouse book as downloads, and can stream the 3 dvd set (about 6 hours total time!) I’ve just finished the 2nd dvd and looking forward to the third, but he really explains a LOT on them about the hows and whys, what to NOT do, etc. Only costs $35  here on permies, and SO worth it if you truly want to go underground. I think a lot of his experience can translate to earthbag... especially stuff like making sure every drop of precipitation has an unbroken slope to drain to earth.

I wish the best for you. Hadn’t considered earthbags too much myself in Missouri, although out in more of a desert/sandy climate I’d probably use them if no/little wood was available. Seems easier than making adobe bricks, although rammed earth looks pretty interesting too. But, staying in Missouri, for long term/retirement home the only way I am seriously considering is Oehler style/wofati/something along those lines.

Whenever you start your build though, even just breaking ground, please do post and document as much as possible/practical... might get  a YouTube channel or blog running and grow some fans! ;-)

Leif

Oh, another thought... if possible, try building a small structure first, like Mike’s original $50 house. You’ll lean a lot, and the addition(s?) will probably be of much better quality as you get your system down and your production speed up. :)

Lief, I actually just purchased 45 acres of south to southwest slope...basicly 3 ridge tops in sw / s central mo.  love the area.  Come on in the waters fine!