Earthbag Scoria Casita

Here’s another great project. This small domicile demonstrates how scoria homes are faster and easier to build than bags filled with soil, and more insulating. This doesn’t mean standard soil-filled earthbags are obsolete. There are pros and cons to each system, however, I strongly encourage using scoria bags (or pumice or other suitable lightweight fill material) if there’s an affordable supply. Thanks to Joe for taking the time to document everything and share what you’ve learned.

“Hi Owen. Wanted to let you know I just uploaded 10 new videos on my YouTube site. One is a portable solar water pump, all others are on our earthbag building.

I’ve been keeping close track of our labor and expenses. We’ve only been able to work on the building for 5-7 days at a time, several times a year so it seems to be taking a very long time. However, I added up our hours so far and was pleasantly surprised. To get to our 8′ height, ready for the bond beam, including digging the foundation, laying bags, framing and providing lintels for several windows / door openings, putting in a main beam with floor joists for loft:
392 hours is only 9.8 40 hour weeks. If you could extrapolate this to a crew of 4 this would be about 2 ½ weeks!!!

Thanks once again for your advice, and thanks to you and Kelly for keeping up your wonderful earthbag sites. Feel free to use this info.”

You can watch all his videos at Festimr’s Channel. (Required viewing for serious earthbaggers.)

Using Scoria for Earthbag Building (Good overview of the benefits of using scoria or pumice.)

7 thoughts on “Earthbag Scoria Casita”

  1. We have a lot of laterite in the area where I live, so I am thinking of using a mixture of soil/laterite, with more soil. They actually call it ‘gravel’ here and it’s the standard local building material mixture to make the ‘clay’ building blocks. Is there any way to tell early on if shifting will be a problem? I don’t want to take the time and effort to strap things down if it’s not necessary, but I also think “Well, it won’t hurt…”

    Also, I noticed that he had tarpaulins covering the base of his walls; what is the purpose of that? Is it always necessary? It’s not something I have noticed in other videos, though I could have simply missed it.

    • The best way to learn is by doing it. Start making test bags and then build a demonstration corner so you can get hands on experience. It won’t take long and you’ll know what to do.

      He was tarping the walls because there’s harsh sun in New Mexico. Bags can start breaking down in a few weeks.

  2. Very good videos and very helpful. Is it necessary and/or wise to use the strapping when using scoria because of the fact that the scoria bag does not hold it’s shape well?? I’m debating on the best material to use – scoria or clay/sand mixture. Scoria is a little more costly than the clay/sand for me but if the insulation is better, I would spend the extra and go with scoria. Oh, the choices! lol

    • Strapping scoria bags is recommended because they’re lighter and could more easily shift. Scoria is excellent in cold climates. The R-value isn’t the greatest actually, but it still works because the walls are so thick. And like I said, there’s way less labor. It’s like moving bags of popcorn. I’d use scoria if I still lived in the southwest US.

      • I live in Indiana so maybe not scoria. I called a hauling company and can get blue, brown and I think gray clay pretty cheap – $12-$14/ton. That seems like a lot of clay especially if I were going to mix it with sand, etc. What do you know about the different clays? Are certain colors better than others??

        • Color is not the most important attribute. Identifying the type of clay requires testing. Plus, buying clay requires lots of mixing, which is a lot of hard work. You’re better off with suitable subsoil, road base or crusher fines. These materials require no mixing if you get the right kind. Make a test bag to see if it dries into a hard block.


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