I want to talk a little bit more about these mesh bags that are used in the hyperadobe system. It’s the hot new development. Let’s take a close look. The open weave allows the soil to dry much faster. They’re lower cost. They’re almost as strong (as poly bags). They’re less expensive. You don’t necessarily need barbed wire between courses, because the soil will go through the mesh and one layer will bond to another. So you can save a lot of time and money on the barbed wire. You pin the corners in the same way with a small stitch. You don’t want a large stitch or you’ll have a recess that you have to fill with plaster. Also, I wanted to talk about the bucket chute we’re using. This is a 3-gallon size. It’s smaller than the other size we’re using (for poly bags). We took a stainless steel bucket, cut the bottom off and filed it to get rid of the sharp edges. Also, we cut the handle off – the attachments for the handle.

Almost everything about these mesh bags is more positive than the white poly sand bags most people use. The mesh is stretchier, so it’s a bit more effort to get it on (the bucket chute), but not much harder. After it is filled and stretches, it’s the exact same size as our other bags (which are standard 18”x30” measured when empty). So you can use them together like we’re doing on our cool pantry. [Example: gravel filled poly bags on lower courses, mesh bags with soil above.] They’re very strong. We tamped this last course very, very hard and there were no tears. So again, we think this is the future of earthbag building possibly, one aspect of it anyway. These are bags that would have been thrown away. We bought them inexpensively – about 6 cents. There are very few alternative uses for these. We bought them at the farmer’s market. So this is about ¼ the cost of white poly bags (polypropylene bags). And they’re just as good if not better. You can also buy this material in a roll and lay down tubes, which is the fastest way. But the bags are good because it’s a recycled product that’s less expensive. So we’re very happy with this. We just did one course on the cool pantry, we’ll show you here, and it’s incredibly strong, very good system. We’re very happy with it. Come to our Earthbag Building Blog and you can read all the details. We’re reporting on this development in a lot of detail, because it’s such a great idea.

Naturalhouse YouTube channel with dozens of videos and many more in the pipeline.


Comments

Mesh Bag Details — 25 Comments

  1. I’m in Taiwan, I am planning to build a 15MX6M rectangular earthbag house in hyperadobe system , can you tell me what mesh bags(or rolls and lay down tubes) are good in the hyperadobe system?

    the mesh bag/mesh bag roll show in the photos, can be good used in my hyperadobe building?

  2. Given that this material is a bit more stretchy than the polybags, would you recommend building with bags or tubes? This was posted quite a while ago, so maybe only bags were available then, but an Internet search has revealed quite a few options for raschel tubing now.

    Apologies if this is addressed in the video – I cannot get it to play right now (slow Internet connection).

    Thanks!

      • The company in Canada has a good price, plus you’ll rest easy knowing it’s the correct kind of raschel mesh. Search our blog for keywords Discount Mesh. I think they’re the largest supplier now of raschel mesh for earthbag builders in the US. (We have no financial interest in any of these companies.)

        • Thanks! I sent an email off to the Canadian company but will check on Discount Mesh as well. This is a much more practical option for me here in Ghana as barbed wire is incredibly expensive! Will keep “digging” through the site for more ideas.

          • Just for clarity: The Canadian company is the company mentioned in the Discount Mesh blog post.

            Kelly and I both believe hyperadobe building using raschel mesh tubes is the fastest, best earthbag method. We have lots of articles on our blog about hyperadobe.

          • I emailed with Maurice this morning and he’s getting back to me on pricing. The mesh makes perfect sense, but one thing I am confused on is the filling and tamping of these long tubes. Do you just…bunch up the material along the outside of the bucket chute and pour, pour, pour, tamping along the way? Do you just measure out the length of mesh tubing you’ll need for each row (adding a little extra length at the end to allow for shrinkage when the tube is filled), then cut it, close off one end, and then start filling it?

            I’m sure you’ve covered this here, but your website has *so* much information (not a complaint!) that I sometimes get lost in all the pages.

  3. Thank you for your answer!
    When you say “stabilize the soil” do you mean with Portland cement or lime? Nader Khalili suggests that but most of the other experts don’t seem to like the idea of using cement.
    I was thinking that in the tamped poly bag there would be no chance for further change of shape even if affected by water. Kaki Hunter and Donald Kiffmeyer say in their book “Earthbag Building, The tools, the tricks and the techniques” that the poly bags are a sufficient mechanical stabilizer and they can actually tackle flood. This is the part from their book where they talk about this issue:

    “While our little Honey House dome was still
    being finished a flash flood filled it, and all our neigh-
    bors’ basements, with 10 inches (25 cm) of water. The
    base coat of the interior earthen plaster melted off the
    walls from 12 inches (30 cm) down. Since the floor
    had yet to be poured, the floodwater percolated into
    the ground.
    The bags that were under water were soft
    enough to press a thumbprint into but not soggy. We
    supposed that under the extreme amount of compres-
    sion from the weight of the walls above, the earth
    inside the bags were able to resist full saturation. As
    they dried out they returned to a super hard rammed
    earthbag again. The bag stabilized the raw earth even
    underwater. Had the bags been compromised by UV
    damage, it could have been a whole other story.
    Nader Khalili had a similar experience in the
    sunken floor of one of his earthbag domes. Floodwater
    filled it about two feet (60 cm) deep for a period of
    two weeks. He documented the effects in conjunction
    with the local Hesperia building department and
    made the same observations we had. In essence, the
    bag is a mechanical stabilizer, as opposed to a chemical
    stabilizer such as cement, added to the earth. The
    bags provide us with a stabilizer as well as a form
    while still granting us the flexibility to build with raw
    earth in adverse conditions.”

    Of course in the above cases the water had affected evenly the bags and not only one side or one spot.
    On the other hand Khalili suggests using cement in order to avoid problems related to moisture or flooding!
    I am a little confused!
    Any ideas?
    Thanks

    • Both lime and Portland can be used as a stabilizer. I think most natural builders would agree that lime is preferred. Maybe Khalili used cement to satisfy the code officials.

      One risk with domes is a roof leak (due to a crack in the plaster, for instance) that creates a soft spot in one area. Moisture could get trapped in the wall and more and more water could accumulate during each rain. The soft spot could grow in size over time and possibly lead to structural failure. This is a problem that occurs inside the wall, not just on the floor as you’re describing it.

  4. Hi.
    I am planning to build a small dome in Greece in the coming summer. Initially the plan was to use the classic poly bags, but now I am really charmed by the mesh bags for various reasons.
    My basic concern is however is what will happen if those bags are affected by moisture of big amounts of water in case of flooding. Would water make the soil so soft that it would escape from the bags and put the whole structure at risk?
    I was planning to use a rubble trench for water drainage and place the first layers of bags below the earth for better resistance to earthquakes. Also I was thinking to protect the first few layers from moisture by placing a water-resistant sheet around them. You can see the plans on my blog:

    http://lokroi-dasos47.blogspot.com/

    (Unless one is a Greek speaker they would not be able to read, but the plans are there.)

    Could it be a solution to use poly bags for the low rows and mesh bags on the high rows?

    Thank you

    • I’ll look at your plans later. Most domes are stabilized to prevent collapse in case of roof leaks. The soil doesn’t have to escape the bags to cause failure. All the bags are in compression with lots of weight bearing down, so even a small soft spot could settle and cause major problems. So it’s best to stabilize the soil. You could use mesh or solid weave bags or tubes, Solid weave tubes are the strongest and would be the best choice in earthquake zones.

  5. As we work on our projects, this site seems to be a great find! Yes, we can. Mesh bags are the best way to go, it looks like, since the soil can dry out and cure faster to set up. Interested in helping us and National Christian Assocition in our work? Let us know. Redbird Band of Cherokee, National Christian Association, PO Box 775, Pineville, Nc 28134 redbirdband.bravehost.com April, 2011

  6. Hello, this is interesting this new bag youve found. Where can I purchase these? I think I want some bags and the roll. I am ready to get some!
    Thanks!

    • Search our blog for “mesh bags”, “hyperadobe” and “raschel”. We’ve listed several suppliers. We’re also collecting samples and testing the bags to determine the best value. Stay tuned… (could be months away).

  7. We hope to be able to do some testing with our northeast Georgia clay and sample mesh tube material this weekend or next – I’ll definitely let you know what we discover. For curing, would you recommend putting the test bags on an elevated platform (perhaps a pallet) with a tarp covering them?

    Doug

  8. Hello Owen! Very informative. Is there a technical name for this type of bag? I’m planning on building my home next year and this would definitely help to reduce my costs.

    Thanks, Matt

  9. Pingback: Mesh Bag Details (via Earthbag Building Blog) | Seeds-2-Sow LIVE Online

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