posted 6 years ago
I hate to say this, but the best thing you could do is remove tires from the equation.
There are quite a few threads on this site that talk about tire toxicity. Cancer rates in the industry are ridiculous. If you need further dissuasion, either go into a tire store, or stand in the middle of your tire pile on a sunny day, and trust your nose.
I would suggest looking into insulated concrete forms (ICF). The idea is, and it accords with temperate climate earthship building, that the form stays in place as a layer of insulation to separate the thermal mass of the structure from the ground, which is subject to seasonal freezing.
I wouldn't use concrete, however, but rammed earth, ideally, just like you'd be doing with tires, only you'd layer up inside the form, and then either run a tamper across it or use a manual one, lay down the next layer and repeat until complete.
You could also use regular forms like they use for concrete and do the walls section by section. In that way, you'd be buying less form infrastructure, although if you wanted to insulate outside your thermal mass, that would be another step before backfilling.
If you do decide to use tires anyways, please either design your walls so the tires are completely encapsulated, such that air exchanges through the mass don't result in the tires offgassing into the structure. This could also be achieved with an over-pressure internal environment, where more air is pumped in, such that offgassing is pushed outside of the structure.
Let us know how it goes, and good luck.
-CK
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein