The library will have books that can tell you about this common way of building a foundation.
As with any type of foundation, remember to tamp the gravel well and to make an adequate drainage system around the house. The creosote used in railroad ties is toxic, so you may want to use these for outdoor walls, sheds and furniture.
You may want to set these on a tamped, gravel-filled trench to prevent possible rising damp. Pound earth into the tires with a big sledge hammer. Stagger the tires on top of each other like you would bricks. For more information on this, look up "Earth Ships" at the library.
The white woven plastic seed or fertilizer bags are basically forms for rammed earth bricks.
If you're building where it's very dry, this type of foundation can be laid right on the tamped ground. If not, it's best used as an above ground addition to a stone or concrete foundation. Or build it on top of a gravel filled trench, because the earth in the bags may wick moisture.
Bags are filled while in place with slightly dampened, sandy earth. The tops of the bags are secured by folding them over and pinning them with a nail, or folding and leaning them against the last filled bag. Then tamp them well. Pound sharpened sticks or bamboo into the bags, so that the sticks protrude out for the cob to hold onto. The bags will disintegrate quickly in the sun, so cover them with plaster as soon as possible. You'll be surprised how well plaster will stick to the woven plastic!
I have heard that you can buy rolls of continuous bag material before it's been cut up for bags to use for this type of construction.
Building with these and with agricultural bags are systems developed by Nader Khalili. For more information on this contact: 0376 Shangri-La Avenue, Hesperia, CA, USA 92345.
When burying the pipe for the electric and/or
rest the rocks on other rocks rather than on the pipe.