Earthbags- what kind of materials are ok?

All I keep seeing is people talking about woven plastic bags, which can be pretty expensive. I've found a source for burlap coffee bags that are relatively cheap (about 80 cents per 30"x40" bag). Would these be durable enough to make a home with or would they degrade too fast? burlap bags

Meran Moore wrote:All I keep seeing is people talking about woven plastic bags, which can be pretty expensive. I've found a source for burlap coffee bags that are relatively cheap (about 80 cents per 30"x40" bag). Would these be durable enough to make a home with or would they degrade too fast? burlap bags

My understanding is that they can be used, with the caveat that they should be used with a proper "adobe" mix or stabilized with lime or cement. They will eventually degrade, but by the time they do, the adobe or stabilized earth will have hardened to the point where the bag's tensile strength is no longer required. Many people buy the woven polypropylene bags as misprints at a discount, or collect used bags. Farmers/ranchers often have many, because they're used to hold animal feed and other agricultural products.

Before you buy anything, however, spend the money on a good earthbag building book or two.

I just read this book:

Earthbag Building: The Tools, Tricks and Techniques (Natural Building Series)
by Kaki Hunter and Donald Kiffmeyer
Link: http://amzn.com/0865715076

I understand that it's fairly highly regarded, and I learned a lot from it.

Kevin

Have you looked here: http://www.naturalbuildingblog.com/ They have a lot of info, free plans, cheap blueprints, and a good instructional youtube series.

Coffee bags should work as long as they are all the same size and not too big for stabilized material. You are essentially making a soft-form rammed earth. I think in a lot of ways they would work better. Poly feedbags fail spectacularly--once you get a small hole you are done and need to get a new bag. I wouldn't use natural material as the bottom layer, though.