The Owner-built Adobe House

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You now need a smooth, level surface on which to cast bricks, a mud mixer, emulsified asphalt, a bale of straw, a garden hose and nozzle attached to a water source (or a large barrel of water), a shovel, a pick for breaking hard ground, a rake, a trowel, and a large contractor's wheelbarrow.

To lay out my adobe bricks, I leveled a 30 foot by 40 foot (9 m. X 12 m.) area with a small tractor. I found this most satisfactory. Without leveling a large piece of land, however, you can cast bricks on a flat 8 foot by 3 foot (2.4 m. X 0.9 m.) casting surface made of 3/4-inch (1.9 cm.) plywood and 2 X 4's, or you can cast directly on large, level, 3/4-inch pieces of plywood.

Next, to mix your adobe mud, I recommend that you purchase a contractor's plaster mixer. This is a large gas-powered mixer with turning blades used by contractors for mixing mortar and plaster for house construction. A cement mixer does not mix the adobe mud thoroughly enough. I feel strongly that a plaster mixer provides the best method for mixing bricks. After much searching, I found a rental equipment operator willing to sell one of his used plaster mixers for $300. If you intend to buy a used one, start with rental equipment operators, then call masonry contractors and firms specializing in used machinery.

When you are ready to start production, get everything — your pile of dirt, bale of straw (from a local feed and farm supply store), 50-gallon drum of emulsified asphalt, and plaster mixer — as close together as possible. In addition, try to keep the distance between the mixer and the brick-casting area as short as possible.

When you are ready to obtain soil from your site, you should try to blend the different layers of soil to make a uniform mix. One way is to combine the different layers in a pile with a shovel, and then transfer this mixed soil with the shovel into your mud mixer. I don't care for this method because you must move the dirt twice. I found the best method is to create separate piles of each layer with a tractor, then shovel equal amounts from the various layers into the mixer.

If you intend to mix the mud by hand, pile the soil in a 3- to 4-inch (8-10 cm.) layer, add water, and "puddle" into a thick mud with a hoe. Mix thoroughly. When it is uniformly wet, add a 3-inch (8 cm.) layer of straw, and mix. Place in a wheelbarrow with a shovel, mix in the emulsified asphalt, and pour in the molds.

If you are using a plaster mixer, put 7 to 8 inches (18-20 cm.) of water in the bottom, then add about 80 shovelfuls of soil. Add enough water to make a stiff mud. Beat the mud until the lumps are gone, then slowly add emulsified asphalt . . . about 2.5 gallons (9.5 L.) per 20 bricks. Let this mix a couple of minutes (the asphalt will not darken the mud). Finally, add the straw: about 1 part straw per 5 parts of soil. I simply cut the straw in 4- to 6-inch-long (10-15 cm.) pieces and placed it in a wooden box. When I had the box full, I dumped it into the plaster mixer. When the straw is added, the mixer slows down slightly.

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