Building With Compressed Earth Blocks

[Flying J]

I always wanted to build my own little replica of a homesteaders cabin. All by myself. It didn't have to be huge. The average homesteaders cabin was under 200 square feet.

Over the years I researched all matter of construction types, both old and new....straw bale, earth bag, papercrete, stone, rammed earth, etc... Being in the Southwest, adobe made the most sense. But being so labor intensive, and time consuming, I investigated the similar method of Compressed Earth Blocks, and settled on that.

What is Compressed Earth Blocks? It is exactly as it sounds. Taking plain old dirt or mixtures of earthen constituents,(sand, clay, silt, and sometimes if necessary the addition of cement) placing that mixture into a press, operated hydraulically or manually and squeezed under high pressure into blocks.

 

[Flying J]

I had to experiment with the dirt I had right around this area. I was able to find some dirt that was high in clay content and mixed that with the dirt that I dug out of the ground for the footings and floor of the proposed cabin location. All this dirt was run thru a 1/4 hardware cloth screen to remove large larger stones and debris. I mixed these two piles of sifted dirt together in a small, inexpensive cement mixer. My experimenting revealed that the addition of a small amount of cement helped greatly to strengthen the blocks. Probably 3/4 cup per block. While all these dry ingredients were tumbling in the mixer, I used a pump up spray canister, as I was not near a convenient water supply, to lightly dampen the mixture. Wet material you don't want in this process. Material, when loaded into the press, is best described as humid. Even less than damp.

 

[Flying J]

From this point it is a matter of mixing and pressing blocks. I stacked these on pallets and covered them with cheap plastic tarps. Some people using this method of construction advocate immediate placement of blocks in your walls. I found this leads to too quick of drying and a weaker block. By tightly wrapping the blocks that are stacked on the pallets under the tarp, right down to ground level, allows them to cure slowly, eliminating shrinkage and cracks. Two weeks under the tarps, they can then be exposed to air. However water is the enemy of these things, so they must kept out of direct rain until protected in their final placement.

I started with a cinder block foundation, nothing fancy. This keeps the CEB's from making ground contact where moisture would destroy them. The walls were built like any brick wall. I used mortar between the courses. You can stack them block on block but with out the mortar joint, you have no real way of adjusting your wall to keep it level.

 

[Flying J]

 

[Flying J]

To be continued....

 

[Denim Deb]

That really looks and sounds interesting.

 

[Hinotori]

That looks cool. I've read and heard some of the compressed earth blocks, but never really went deep into the research. We get to much rain for it here.

 

[Flying J]

As I went along building the walls, I kept them covered with tarps to protect the blocks from rain returning them back to natural state of mud.

Once the roof was in place, the interior walls were protected. I could then leave the interior blocks more or less their natural state, which I preferred. The outside would need to be protected from the elements.

Several options here...I could prepare the surface and stucco the outer surface, I could attach another surface like siding of some sort...I came up with the quickest, cheapest and easiest option, (after some experimentation). I treated the outside surface first with acrylic fortifier, available at any lumber yard. It is most often used as an additive to mortar and cement to increase it's strength. I simply brushed it on to the outside blocks. It is very watery and soaks into the surface. When it dries, it hardens the surface, binds it together and makes an excellent surface for paint.

I ended up using elastomeric paint (which you can get in any color you desire). It is basically an acrylic latex paint with a very high latex percentage. In other words it is thick, almost like pudding. This bound excellently with the acrylic fortifier I mentioned earlier in the process. You roll this on thick and it leaves a very durable rubbery, water proof surface. It is now in its second year, and numerous hail storms, snow and rain storms, relentless beating sun and it is as tight as it was the day I put it on. No peeling, cracking or leaks.

I ended up treating the interior surface with the same acrylic fortifier. It dries perfectly clear and leaves only a slight satiny sheen, allowing the natural look of the earth blocks, but making for a clean tight surface that wouldn't pick off.

 

[Denim Deb]

What does the inside look like?

 

[Flying J]

I finished the enclosing process by building doors, windows and shutters. All wooden trim as well as interior furnishings were built from inexpensive rough sawn ceder fence pickets. This added to the rustic look I was after as well as being inexpensive. The windows themselves I made of simple angle iron frames with glass set in using 100% silcone sealant. Everything was just pieced together and built as needed. The sink is a galvanized feed bucket. Hole drilled in the bottom with a drained installed in the bottom and piped outside. My water supply is a 5 gallon jug gravity fed into the sink, using a pull chain to release the water. Lighting is kerosene and candle lit. As remember, this is meant to be a throwback to a simpler time.

Ultimately a dirt floor was a bit too rustic for me. I ended up spreading a 2 1/2 inch layer of standard mortar mix, dry, over the floor. Then soaking it down with a hose. Once hardened made for a nice cement floor. A few cracks only adds to the affect.

Oh, and before you ask, the outhouse is set to be completed this fall. Ha!