The wall is underway! Last wednesday, a crew of five people started working on it, with Ian’s supervision and guidance. (Ian is a friend who is a professional mason whom we have hired to run this project.)
Digging the hole for the root cellar produced this fantastic pile of dirt.
We happen to live on some really great river-bottom clay-silt, which turns out not to need any amendment for this type of construction. Woo! So we sprinkle the pile with water until it is lightly moist but not sticky, and thus will tamp down neatly and retain its shape when dry, and then set to work.
First, we cleared the fenceline along the course of the day’s planned work.
Then, you dig a trench slightly wider than and as deep as one bag, that plots the course of your wall. One need not do this all at once; we are trenching as we begin each new section of wall, so that we don’t have to take the whole north fence down for a month while we work.
Our wall is curved in a ratio of 1:3.5 (one foot of side-to-side for every 3.5 feet of length), which will mean we do not need to use pillars or pileasters because it will remain stable without them. 1:4 is the minimum ratio to maintain this integral strength, so we are going with a pattern that is somewhat stronger than that by being tighter. We like the sinuous snakey thing going on here.
laying the first few bags. We cut the bottom off a couple plastic 5-gal buckets, and pulled the handles off. This gives us a form to use to fill bags. We put the bag through the bucket, smaller end of the bucket on top (so that it will come off again), put the bag into it like a trash can, and then fill the bag with earth. Then the bag top is folded off in such a way that the opening is fully sealed (it’s a burrito-fold with the bottom end, coming toward the sky, done last). You lay the bag down overlapping its neighbor slightly, so that they seal up (more or less) when tamped. When starting, you fill two bags simultaneously, and then lean them into each other so that their open-folded ends press on each other, keeping both bags sealed shut. Ian decided we needed a name for that technique so that he could think about it, so by the end of the day, we were calling it “drawbridging.”
Ryan, Ian and Rev filling bags.
the first course is down.
then you tamp all the bags down until they don’t squish anymore. This compresses them into a brick-like consistency. Here, Rev is tamping bags.
Then you use four-prong (not two-prong) barbed wire as mortar, to hold the courses of bags together. we found a fencing supply store (El Ranchero Supply in Belen, for you locals) that would sell us four-prong barb in rolls with handles, which is awfully nice in terms of people not getting stabbed quite so much with the wire. You lay two rows of barbed wire along the top of the course of the bags. We anchored it with bricks along its length so it would stay put while we were working. You make sure the down-poking barbs poke into the bags as anchors.
Then you lay the next course of bags, as before.
As the day went on and the wall really took shape, we climbed up on top of it to fill bags, and switched from using shovels to move dirt, to using large coffee cans and crews of two people per bag being filled; one person on the ground with the wheelbarrow full of dirt, handing up cans-full of dirt, the other on top of the wall stabilizing and filling the bag and then laying it into place when it was full.
As you go up the wall, also, you leave the ends a little shorter each time, with a loop of barbed wire hanging out to use as mortar later, so that it is a simple matter to tie back into the wall on the next day’s work.
Ian tamping bags:
At the end of the first day, we had 15 feet of wall finished, and we had all learned a lot about the process!
the ever fabuous Rev
Details i have thus far left out: joints & edges. You have to lay the bags in such a way that you don’t end up with a “running joint,” or a seam that runs right up the wall. This is unstable and will crack or break later. Instead, they should be laid alternating, as bricks generally are (and all these are is really big homemade bricks). Also, the little tab-ends of the bags will stick out the sides. You come back later with a brick and pound them into place, then tuck them into the wall and plaster over them to create a smoother surface.
On the second day’s work, we again began with trenching and laying the first row of bags. When that was in place and the second row was going in and we had hit a rhythm, Ian began the first stage in plastering the finished parts of the wall, which is the application of a thin clay slip, which will later hold the plaster onto the bags. During the day on our first work day, we had taken clods of solid clay, of which we have an abundant supply in our dirt, and put them in a bucket of water. We let them stand a few days, then Ian massaged these into a thin clay slip, which we applied with a plastering brush.
and the wall started to look like an earth wall.
i got in on the action, and ended up nigh covered in mud speckles. it’s a great process. two more coats of plaster will go on over this, the straw-mud plaster out of which we will sculpt bas relief on the wall, and then the final coat of limewash to allow it to survive the ages.
Tattersall approves of the wall.
the coffee-can method proved so much faster than the shovel method that we abandoned shovels altogether much earlier on saturday, and got more done.
at the end of the day, not having had quite enough fun with building materials yet, we decided to put in an arched window, for beauty’s sake. Ian used a roll of earthbag tubing as the form.
we laid a course of bags right up to the form from both sides.
then Ian filled half-bags and laid them along the form, pounding them into the arch shape (radiating out from the center of the tube) as he went.
Bags are applied evenly from each side until the arch is ready for the keystone bag.
pound that one into place, and then you have an arch!
we laid one more course of bags over the top of the arch, to create a smooth line along the top of the whole wall.
this thing is brilliantly solid, as well as beautiful.
Rev on the wall:
and corn and sunflowers in the garden, while we’re at it!
even more process pictures are available here, if you’re interested in seeing more of what the whole thing looks like.