Rammed Tire Foundations?

Does anyone know how to do a foundation for a straw bale barn from tires rammed with earth?  Or more, really, I've got the general idea of digging a shallow trench, running two or three courses of tires, and then somehow putting straw-bales on top, but I wonder what, if anything, you put between the tires and straw bales.  I've gotten two trailer loads of tires so far (~50 tires) and last time also started picking up truck tire inner tubes because I figure the thick rubber could be useful as between the tires and straw if some sort of vapor barrier is needed.

Granted, this is a barn, and small at that, as it just needs to hold two cows and a few goats, and will be my first foray into building with straw bales (or really anything except wood- I've build a deck and shed from wood before).  I expect I'll make mistakes, but that is OK to me, because in a few years I hope to have more cows and would maybe need a larger barn (or some sort of portable, in the field shelter), but I don't want to make a mistake that will cause it to rot after just a year or something...

MMM Im new to this too. But have done alot of research. Why don't you just place bales on top of tyres and then secure with hazel rods through the bale and down to tyre? And then when all bales are up secure with straps. They wont go anywhere. Are going to plaster both the tyre and bales? That would really finish it off and look great. Good luck

I posted this link on another Forum Post but it definitely applies here.

It's common details pertaining to straw bale construction and rammed earth tires are included.

http://www.ecohabitar.org/PDF/strawbalebuildinguide.pdf

The only problem with the pdf is that it uses rammed earth tires to make a raised building, which generally isn't what you want in a barn.

The biggest problem with rammed earth tires by themselves is guaranteeing that they're level and stable over long periods of time. If you draw a beam between two rammed earth walls for a floor then only frost heave and landslides could possibly move it.

If on the other hand if you just put up a regular wall above a rammed earth foundation, any instability will come through as a moment at the support 10-15 feet above it's base, almost guaranteeing problems.

If you're still sure you want to used a rammed earth tire foundation, your moment connections will have to be seriously strong on both top and bottom of the wall. Beyond just the hazel stub to hold the bales in place, you would probably need at least one wall pin per tire, I'd personally probably try two, connected through the tire just below the top row. At the top of the pin you'd want to screw them in instead of nailing them. This would probably bring your spacing down from the common 20" to 5-15" O.C. for the hazel pins depending on the tire size.

I'm saying this from an architectural perspective that's what would feel safe. I haven't seen the detail for something similar, and an engineer might be able to calculate the needed support and formulate a structural detail.

You may be able to find a book with the info you need,here


http://www.grannysstore.com/

The best two books I have seen on the subject are – --The Straw Bale House by Swentzel and Steen and – – – Straw Bale Building by Chris Magwood and the other guy . I should know this I spent several hours with these guys and helped load up their demo wall that was traveling the country on a book tour. The first one has plenty of information about building in drier environments. The second is written by two guys in Ontario Canada and goes into much more detail on dealing with water, vapor barriers etc. The first book is a visual delight but the second is much more technically advanced. Both have been in print for about a decade so there have probably been improvements.

What about the concrete bond beam on top of the earthships. Then you can frame from that and do your straw bale. I would love to do earth bag or tire foundation but not code approved, maybe if that changes then for sure only issue I see is insulation. Straw is great but you have to keep the bales up 18 " off the floor so you would loose heat out the tire base wall unless you insulate it somehow?

Guess we should know if you are doing load bearing straw or infill? I just borrowed chris magwoods straw book, looks good.

Enviroman wrote:
What about the concrete bond beam on top of the earthships. Then you can frame from that and do your straw bale. I would love to do earth bag or tire foundation but not code approved, maybe if that changes then for sure only issue I see is insulation. Straw is great but you have to keep the bales up 18 " off the floor so you would loose heat out the tire base wall unless you insulate it somehow?

Guess we should know if you are doing load bearing straw or infill? I just borrowed chris magwoods straw book, looks good.

That's a good idea.  Concrete is pretty cheap here, just I didn't want to do a full concrete foundation because it would be a lot of stuff to take up the hill, and if some years down the road I decide this wasn't the best location for the barn, it would be a lot harder to get rid of that than digging up tires, even if they're filled with earth, but a concrete beam could just be dragged somewhere else by tractor.

The insulation issue isn't such a big deal for me, the cows will still be happier with imperfect insulation than with being outside in the snow and wind during the night, and they should keep the barn warm enough so hopefully their water won't freeze.

Load bearing walls.

if you can access the earthship books, there are design plans and description for a rammed tire and strawbale hybrid buiding at the end of vol. 3, I believe.  It's for a 100-200 sq ft round building, but the details should be helpful.

I would caution against this approach. There would be nothing to stabilize the tire "bricks" and would get successively unstable each course up you went. Earthships use the packed tires as a earth bermed counter pressure wall, with tons of earth supporting the entire height of the wall, and then with a concrete bond beam on top to tie it together.

Also, goats especially and cows as well somehat, will wreck havoc with the bales. Goats are rough, and rub, ram, chew, and jump on everything.

If i were doing this project i would either:

Build an earthship type underground 3 sided barn if insulation was key

or

Build a simple wooden barn, either sinking the corner posts in a small footing, burying the posts in a gravel and rock filled hole, or making a self supporting structure on pier blocks, or even nothing if its going to be decomissioned relatively soon. If its just about general weather protection, wind, rain, etc.