As far as I understand it, the bags only serve the function of holding the material in place while it sets up. Once the material is set, the bags are more or less redundant. Following this logic, I see no problem with using a linen sack that will biodegrade long after the material it is containing has set.
That being said, I have no experience with this and am not a building professional or engineer.
Hi Maruf, Kelly Hart has a lot of experience with Earthbags. His site has a FAQ section on what can be used other than poly bags here: Earthbag faqs
I notice that he says he doesn't prefer the bags to decompose. Perhaps one of the answers explains why. You can let us know when you find out!
I'm not sure how the bags would decompose anyways (minus if used for the foundation layer) since they should be encased (mummified) amongst air, water and sun by the exterior/interior plaster layers.
I know that what is called hyperadobe is considered much better than the superadobe because of the better bond and probably eliminating the barbed wire altogether. Check it out here: hyperadobe
I wished that I had gone this route when I built as it makes a lot more sense and working with the barbed wire was not always fun. Harder to source it out than localfeed bags which are commonly used, but then I haven't looked recently very hard either.
i agree with the responses, but with a qualifier - its all about what you put in the bags. if you put a mix in the bag that is basically a stabilized earth (and maybe includes cement and or lime) then the "form" of the earth bag doesnt matter, it's just there to hold it together until it gels.
BUT one of the advanatages of earth bag is you can put different stuff in them, and even different layers of different stuff. so your bottom bags may be mostly gravel and sand, or you may not have access to perfect ratios of materials to fill in all bags.
with plastic bags the bags can double as something of a moisture barrier. you can throw anything in them.
with say linen or other biodegradable bags, maybe burlap say -cause you can get them for free, this would only work if you are using the right ratios and mixing it together good. then it's just a temporary form, to hold it together until it sets up as a sort of brick.
Thanks for the link Gerry. Here's her reply which lines up with what Leila wrote
Q: What will happen to the structure when the bags rot after some time? I am afraid that when the bags are worn out or rot then the remaining earth structure will no longer have strength to hold on together and will be vulnerable to damage due to rain, wind, excessive sun (long period of drought).
A: The answer to your question depends on what material the bags are made of, and what they are filled with. If the bags are filled with a moist adobe soil, or stabilized soil, then it doesn't really matter if the bags rot, because the structure will remain solid. If the bags are filled with a looser material, then you should use polypropylene bags rather that burlap or jute, because it will not rot over time.