What about using tires for foundations? In my opinion, earthbags are superior for foundations and walls. If you’re not convinced of this, tamp one tire (the way it’s supposed to be done, which takes 20 minutes or so). Then tamp the equivalent (in cubic inches) in earthbags and see for yourself which is easier. But it gets better, because lower courses can be filled with gravel (double bagged for durability). I could fill and stack about one-half to one whole course of earthbags on a small dome in the time it takes to tamp one tire. That’s a 10 to 20-fold improvement in speed! Swinging a sledge hammer is gut busting hard work. Tamping earthbags isn’t exactly “easy” but it’s way easier and faster than doing rammed earth tires. And with earthbags you can use insulated fill material such as scoria or perlite to create an insulated foundation.

I love the look of earthships and admire all the wonderful eco features, but I’ve learned how the same things (roofwater collection, solar hot water, etc.) can be integrated into a well designed earthbag home. With earthbags you can have these same features at a fraction of the labor and time.


Comments

Tire Foundations? — 10 Comments

  1. How do you contain the foundation? Doesn’t the bag eventually disintegrate or is something special done with the plaster covering the bags below and just above the ground to prevent the foundation from sloughing away? Is this even a problem? you mentioned perlite for insulation. Is what is a good ratio to mix with the gravel in a foundation bags?

    • The earthbag foundation starts below grade on a rubble trench. It is keyed into the earth. Each course is connected with barbed wire so they can’t slide. Use gravel bags on lower courses where water damage is a concern. Keep the bags plastered to protect from UV damage. US highway department (Dept. of Transportation) testing showed polypropylene bags can last at least 500 years below grade if protected from UV. One of the biggest advantages is cost savings. You can save thousands of dollars on the foundation alone by using gravel bags instead of concrete. For these and other reasons gravel bag foundations are now very popular among natural builders. Ex: The width of gravel bags is exactly the same as most straw bales.
      How to Build Dirt Cheap Houses http://www.naturalbuildingblog.com/instructable-how-to-build-dirt-cheap-houses/

      Perlite is a good insulator that resists moisture, however building with perlite is experimental. There are numerous ways of using perlite to create insulated foundations. The best method partly depends on what materials are available and the temperature. One option in cold climates is to tie tubes filled with perlite onto the face of the gravel bag foundation. Search this blog for keywords insulated foundation or cold climate.

  2. Hi, I am building an earth bag House, Workshop and Guest cottage on my plot in Maun Botswana. I am having the 3 chamber Earthbag sewn up in Maun and was wondering if I need to tamp the bags as the soil I am using is mainly Kalahari Sand mixed with clay? I am also looking for a good adobe mix for plastering inside and out? I would apreciate your comments. Thank you

    • Tamping is recommended so the earthbags are harder and stronger.

      Talk to potters, soil engineers and others in your area who work with clay. Do lots of experiments. Use wide roof overhangs to protect exterior earth plaster.

  3. I have read that it is fine to build a two course tire foundation to build a strawbale house on right on top of the ground without having to use a foundation trench. Is that true also for earthbag foundations?

    • You always have to account for site conditions: frost depth, soil conditions (expansive soil? or good drainage? French drain needed?), water runoff/site grading, seismic, etc. In general, rammed tires and earthbags would be handled the same, which makes sense since they’re both containers holding soil or gravel. But between the two earthbags are faster and easier.

  4. hello, curious about the basic principles of creating a dome style home,in canada…..alberta.bound location where.temps.can get to-30c.

    Does it make more sense to have thedome home down below frost line (here it is 3ft) and can you direct me to plans for a small style home with maybe a loft design for a 1-2person style………with the possibility of a cob oven and a rocket stove design incorportated in it or is this better suited with a real wood stove .

    Books, web sites, blogs or any direction of all that would be offered would be greatly appreciated .

    thanks for your time

    Regards,

  5. Thank you for pointing that out, I agree time and energy saved by using earthbags over tire is very significant, and as natural buiding is mainly work labour, it therefore reduces buiding “costs”. However, do Tires and earthbag have the same mechanical caracteristics, and aren’t there any advantage of using tires over earthbags in a foundation?

    • I can’t think of anything good to say about building with tires. I’ve seen abandoned earthships firsthand, and have heard how people watched their dream of home ownership slip away due to the years of hard labor required. They’re definitely not “free” when you factor in all the labor. Very few people are cut out (physically able) to build tire houses. They’re sort of a trap if you think about it, luring the unsuspecting. And what about the tire dumps left behind after people give up? They become a public nuisance. Another complaint I have is how some books tend to treat all natural building methods more or less equal. They’re clearly not. Why use tires when earthbags can serve as foundations, retaining walls, work in wet environments like greenhouses, hold back floods, withstand hurricanes, excel in hot and cold climates, and on and on.

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