This weekend we helped some friends for a day building their house using HyperAdobe. HyperAdobe is a super quick method to build a house using bags full of earth as bricks.
So first you need your earth. The earth should contain about 70% sand and 30% clay, and you may not have to do any mixing before filling the bags with your earth, depending on its content. To do a rough field test of your earth, check out this previous post – how to test your earth. The proportions do not have to be exact as the bags and the compacting process will help hod everything together, but best to make some blocks from your mix beforehand to see how they hold together, see if they cracks or fall apart on drying. Check out my cob test for some ideas on testing an earth for building
All you need to do before you put the earth in to the bags is make sure it is a bit wet, so that when you grab a lump and squeeze it in your hand, it stays together.
You can start filling your buckets with earth now if you like, just a couple of preps to do before you start making your first adobe brick…
Take your roll of vegetable bag and measure the length of the wall. Make sure to leave space at either end to tie the knots to hold everything together. Tie one end maybe then measure the wall, then leave the other end open to begin filling with earth later on.
Below is the tool you need for filling the bags. It is a bucket with the bottom cut off, and a metal tube attached below. Pull the vegetable bag over the metal tube and up to the bucket, with the knot at the bottom.
Have some one on the ground handing buckets of earth up to the person with the filler. At the beginning make sure to push the bag right to the edge of the space you are starting at. You can keep your foot under the bag as shown below. Just pour the earth in to the funnel, let it fall, lift the funnel a bit and walk backwards, making sure to shake the earth into a large even lump, you will compact it later.
Once you get to the end of your wall, tie off the sack.
When two walls meet, make sure that they inter-lock. This is really important to keep them both strong.
Next you need to compact your brick. Do this with every layer after the brick is laid. Firstly go along with your compacting tool and use the weight of it to tap the wall down. Then spray the top of the brick with a bit of water and go again using more force to make the brick level. Use a line to show the level, and have someone helping out to say where to apply more and less force.
When you have done 7 layers, give them some time to dry, and use a large mallet to bash the sides in to a nice flat wall. You can easily make a mallet using wood if you do not want to buy a plastic one.
Door frames should already be in, and covered a bit to keep them clean, make sure to remember when you reach your window level, and put the frames in when necessary. To raise them up a little bit you can add a bag of earth, but not completely full, and lift the window exactly the height you want.
If you get any holes in your bags just tie them up with string
As mentioned above, this is a really quick way of building with earth. With just 5 people we got to this level in just 5 days!