The first method used to seal the roof is polyethylene film later they recommended using EPDM Pond liner. I'm fairly sure the pictures sito007 posted are of Mike Oehler author of the $50 & Up Underground House Book. He also has a book on "THE EARTH-SHELTERED
SOLAR GREENHOUSE BOOK" which some example pictures are posted above. After reading the post above I got to thinking about it and rented "The Low-Cost Underground House Workshop" last night from: http://smartflix.com/store/video/3007/The-LowCost-Underground-House-Workshop
One thing he writes about in the book is using fired or charred wooden post for the vertical supports. He then wraps them in polyethylene. I always thought this wasn't the best way. Of course it is the cheapest. I thought about it and determined that digging post holes in the ground and then filling with concrete would be better. Embedded in the concrete would be metal braces. The post would bolted to the metal braces. It would be similar to a post and beam underground.I read a review by another guy who built one and he said he had to change it. He ended up using concrete to keep the post off the ground.
just throwing this out there, from what i recall some states and a couple provinces will actually still pay people to remove tires from the waste system. some places people used to get upto 3$per tire removed, often paying for much of the building costs of their sustainable home.
even if they wont pay you, it is often easy to get the tires for free. print an ad in a local newspaper etc saying you will pick up old tires free of charge. in places that dont pay you to remove them from the waste system it is usually a company that will charge you per tire to pick them up and remove them. alot of people hate the fee of this service, so offering it to them free is a great way to obtain tires for building with. same way i get my waste veggie oil, just offer a free service.
Got the three DVD's from netflix. They look fairly good. Haven't watched all of them but did scan. They show three dimensional models. Explains design and shows some built buildings. Worth renting.
Coober Pedy is a town located in northern South Australia and is known as the opal capital of the world, as nearly 95 percent of the world's opal supply comes from the local mines. This small town with a population of around 3000 has a unique way of life – nearly half of them live underground. that way too caveman for my boondocks.lol