Friday, May 27, 2011

Back to Building

This year I'm paying more attention to tamping. Before I sure tamped the tops hard enough until the bags were like rock. I also whacked the sides with a piece of 2x4, but didn't do that part as good as I could have. It makes a big difference when it comes time to do the plastering. A smooth, even wall is a much faster-plaster-blaster experience. Takes a lot less, which means fewer mixes need to made up just to make things even.
This years bags will have a much flatter vertical edge
By the way, tamping can be exhausting after a lot of lifting earthen mix. I can only leave it so long too, or the mix in the bags starts to dry out and then it would be too late to get good compaction. I usually tamp after laying about four bags. If you can trick some poor sucker into doing the tamping for you, it would be well worth whatever blemish you end up with on your conscience.

Shown below are pictures of how we close our bags. I fold the top like and envelope, sides first, then ends. They are pinned shut with a nail.

Shown under the bag is the slider I use most often. It was once a door on the side of a grader. It's quite sturdy and I got it for free. The place I work at has a mountain of things torn off of heavy equipment. There's enough stuff there to rebuild civilization. Granted, everything would be yellow and black and with the Caterpillar logo all over the place.

It sure is good to back working on our domes. We have such a short building season and I've been itching to get back at it. We laid about fifty bags last weekend and are off to a good start this year.

Doorway between living room and bedroom. My shop in the background.


  1. Cool! Please keep us all informed of your progress.

  2. Lookin' good! And access to a Caterpillar bone yard can be a very good thing...

  3. Thanks for the pictorial! I always love to see the details of how people are doing their building, and I'm especially interested in how people close their bags, as that's the part I find most tedious. I really like your system - clean, simple, tidy.

    So I guess you're well in your way to being a Master Faster Plaster Blaster. :)

  4. Great work. You're so right, tamping well makes plastering so much easier. I wish there were piles of discarded equipment and parts around me.

  5. Wow, nice Gothic arch! ..and jeepers nice double-height metal-clad shop with dual sliding doors... lucky! My 'shop' is a shitty old garage with 2/3 of one door (chipboard), just enough headroom.

    P.S. We'll be building with straw bale before summer's through, as part of a workshop. Similarly will have to get the hang of plastering.

  6. Hi Muddome,

    The tamping part sounds like a lot of work. Is there a way to make it easier, say using a "jumping jack" or plate compactor or even a log-spitter?


  7. What are you going to do on the exterior? I'm thinking just spray gunite.

  8. Great photos and progress, y'all! Let me know how the side-tamped bags hold up! Kaki Hunter says not to do this in her book for a reason I don't remember. Maybe long-term durability? I hope it holds up for you guys!

  9. It seems as a good old Ukrainian style of mudding. They utilize horse shit plus somefractured hay to mix with clay and use wooden forms for sun-drying.

    Walls became about 50-60 sm in diameter after plastering inside and outside with white clay for extra durability and "aesthetics".
    The only thing I would be worry is mices and/or rats. Those creatures will build a community inside sooner or later.
    But definitive pluses are temperature equalization and insulation. Bc clay in mixture with hay and horse shit after drying will be porous to some extent. Of course windows with openable smal frame in the top required for sanitary ventilation.

    Oh, are u going to build a stove? I would recommend to utilize wall of exhaust channels as divider betveen rooms - works as calorifer in winter.
    I've build a few by myself, so I can draw u some plans.
    Are you going to scrape plastic from inside? Cos if not it might collect humidity and begin to sweat between wall and inner plaster core.