Adobe bricks are essentially cob building blocks, where a large portion of the drying time (which can be significant) is done before the building process begins. They can be used to build a large list of items very quickly, including RMHs, built in furniture, ovens and even whole houses.
To make adobe bricks you need an adobe form. Typically a wood frame, open at the top and bottom for forming cob into bricks. Wet the adobe form by dipping it in water, place it on bare ground and toss in a wet-ish cob mix (literally tossing in handfuls, throwing it down hard will eliminate air pockets). Level the mix off to the top of the form, then pull the form away, leaving the wet brick behind. Wet the form between bricks. Repeat. When dry enough to move without deforming, flip the bricks on their narrow edge to finish drying.
- Make 12 bricks
- 12” by 6” by 3”
To get certified for this BB, post the following as pictures or video (<2 min):
- Show your mix and tools
- Action shot
- Bricks drying on edge
Knocked this one out at the 2019 PEP1 event at Allerton Abbey. Sifted soil to remove rocks. They had clay slip and chopped straw in barrels already on site. Used 3 pails of sifted dirt, 1 pail of straw, 1/3 pail of clay slip and some water to make a wheelbarrow full. Please note that the recipe is site specific so your soils may vary. That filled 8 molds at 6" by 12" by 3.5".
Put some water and slip in the wheelbarrow first. Then added the dirt and mixed with a hoe. Added water slowly (Don't do too much!!!). Then added the straw and mixed it in. Then shoveled it into the forms and poked it in with fingers and used a board as a screed to level them. Left them sit overnight and popped the form off in the morning and stood them up to dry. My bricks are the closest row to the wheelbarrow.
I'd humbly suggest changing the requirements to be 3-4" thick so that a 2x4 can be used to make the forms.
Made some adobe bricks. The sandy dirt was screened and mixed with a bit of clay, straw, and water. It was pressed into the mold. Since the mix wasn't too wet, I could remove the mold fairly soon after and place the bricks on their sides to fully dry.