Building with earthbags is essentially building with adobe bricks without going through the lengthy process of making them. You take polypropylene sandbags, fill them with a moist mix of sand and clay, tamp them down hard and connect the layers with 4 point barbed wire. Then, you cover them over with an earthen plaster.

In reality, I didn't use polypropylene bags. Some Brasilians started a type of construction they call hyperadobe which uses mesh bags, or continuous tubing, made from the same material as the onion or potato bags in the grocery store. They don't require barbed wire, though otherwise the process is just about the same.

As I talk about in the blog posts, my design has been guided by simplicity and efficiency. More than anything, what's been most important to me is to live in a house that I myself, with no building experience whatsoever, can design, build and maintain. A natural extension of that has been the desire to live in a peaceful space. For me that means a home that's in tune with nature, thus limiting the use of imported materials for construction, in addition to those that will be needed later on, such as for heating. Please enjoy reading, ask me any questions, get inspired, and come help and learn!

Friday, August 5, 2011

Plaster and Backfilling and Lintels and Strapping

Work progresses! So beautiful to have another human being helping me. We have plastered to varying degrees everything we'd bagged up until yesterday, backfilled the entire perimeter (you can walk up to the walls! No more climbing in and out of a pit!), and set the first lintel. There's just one more bag layer to go on the north side before the last two final tube layers. I'll presumably finish that this weekend while Kevin is gone.

For plaster we used the dirt from the property. On the outside it is an inch plus thick. Because of the high clay content of my dirt and the thickness of our layers it's cracked a lot. The next layer on top of it will be done when all bagging and roofing is finished. It will have a good amount of sand and will be quite thin. If all goes well, that will take me through the winter. On the inside I did just a thin layer of the same mix to cover the bags. I'm not sure what I'll be doing as far as plaster on the inside so wanted to keep it thin. Also, since there's no weather on the inside of the house, it's not all that urgent. I can finish plastering it next year if I want.

Plastering is fun, easy and relaxing. We were kinda loathe to finish it and start backfilling which is a bit grueling. Eventually, though, we did get a nice system down. Basically we used a piece of 1/2" plywood I had around and some other random things (like the lid of a plastic storage tub and a pretty solid pallet) put it between the scoria and the dirt, filled, pulled up, filled, pulled up etc. The goal was 9" of scoria. We often went above and rarely if ever below. Bag filling is much easier and less scary now that there is solid ground all around.

Once done with that we were able to continue filling bags. We've done two layers over the last two days. First we had to make a lintel which we did by screwing pieces of 2x6 together and placing them on plywood that extends for another 6" or so beyond the end of the lintel. I made the pieces on either side slightly smaller to accommodate the curve. Doing this, however, caused there to be a gap underneath so I stuck a small piece of plywood on either side so that the bag had something solid to lay on. I'll fill it with mud later on.

Today was also time to think about the roof! I'm using 800 lb. break capacity poly strapping to connect the rafters into the wall. The rafters will lay on plywood velcro plates to which they will be super bracketed. Those brackets will be strapped four bag courses down, plus they'll have an additional two courses of bags on top that will fill the gap between the rafters. I'm not quite sure what spacing I'm going to do for them yet, but am guessing the most likely will be 18" on center. I ended up placing a strap every 9" figuring each rafter needs two straps (one on each side of it).

It's amazing how time flies and the house grows!

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