Rammed Earth Tires as Foundation

**esmithers1** · 10-08-2011, 04:59 PM

Good evening. I was looking at some alternative construction and found "earthship" building that basically build into the ground but uses old tired rammed with dirt as the walls. While reading about this type of home (not as appealing as a log home) I started to think about the savings that could be had IF that type of wall could bear the weight of a log home. One of the FAQ's on the website is as follows:

"Q. Do I need to use a concrete foundation under the tire walls?
A. A concrete foundation is not necessary because tire walls are so thick (2-1/2' for rammed-earth tire walls and 5' for tire bale walls). Both the rammed-earth tire wall and the tire bale wall have just at twice (almost 4X for the bale wall) the bearing surface of a standard concrete "footer". The key to the difference is in the "footprint" of the wall. A framed wall needs more footprint to hold up the roof, a tire wall doesn't."

The question is, what is the ability to bear the weight of the log home above. Does anyone have any ideas? Of even the answer?

Thank you

Eric

**esmithers1** · 10-08-2011, 05:01 PM

Let me clarify, I am thinking of building a log home with a full basement (either a walk out back or fully enclosed). I would love to not have to have so much concrete which could save me lots of $$.

**rckclmbr428** · 10-08-2011, 05:28 PM

Unless you have an engineer sign for it, you will have a hard time convincing a bldg. Dept to approve it. Rammed earth works good in low precipitation area, I would imagine water would be as much an issue in NY as load bearing abilities.

**loghousenut** · 10-09-2011, 08:19 AM

You still have to put the bottom of the wall below frost line. If you could get an engineer to stamp a rammed tire foundation for a log home, try to build close to him so he won't have to travel too far every time the building inspector comes out to the site to argue about it all. I'm thinking that even if you filled the tires with concrete and rebar you'd be seeing a lot of fully raised eyebrows. Heck, you see enough raised eyebrows just building this kinda log home.

If you really want to save money on the foundation, do it the way Skip woulda done it. This is the opinion of a guy who made a rammed tire retaining wall for part of the driveway that goes to the log home he is currently building.

**Steve Wolfe** · 01-13-2012, 02:42 PM

My Mom has a close friend in CO that built a beautiful Earthship home near the continental divide. My wife and I along with my Mom visited her about six years ago. It was winter when we visited yet her place was so warm and comfortable inside with no fire burning.

Rammed earth tires were used for her back retaining wall and some of the other exterior walls. Rebar was used to tie in adjacent walls and the use of adobe enabled her to make a smooth and clean transition from wall to wall. Log rafters were used to support the earth covered roof. I don’t remember what she used to seal the roof. She mixed the adobe using natural resources found on her property.

The front of her place is 90% windows so she can take advantage of passive solar. Along the front wall she has an indoor garden that must be 50 feet long. Her Earthship is an “L” shape with the short part of the L going underground. Some of her interior walls are made from a combination of aluminum cans and adobe. This method reduced the amount of adobe required without compromising the strength of the wall.

She is completely off grid and she built the majority of the Earthship herself over the course of 10+years, with some help of course from friends. Her solar system is very modest as she consumes very little electricity. It is an incredible place. Many of her friends are artists whose contributions included stained glass hangings, raised sculptures integral with the adobe walls and massive paintings on the walls depicting wild horses, Indians and landscapes, all in a western setting. She likes her privacy but on occasion holds week long self meditation sessions.

If there was ever a Mrs. Proenneke, she would be it. Tough as nails, resourceful and full of passion, resilience and vision.