We are off to a late(r then I would have liked) start this year. This was primarily because of my allergy and a very rain season. It was also because we got stuck with the roof!
Our primary plan to make a roof out of acacia vigas was deserted when we failed to source logs. We tried using some logs we had lying around. When we did … I stepped back and felt a clear “no” … I felt they were not uniform enough to build a good roof.
I then decided that we would use standard (easily available) soft-wood boards to create beams (charred to preserve and protect them).
… and after we got the beams onto the large room and sat inside it … we felt the structure gained a whole new dimension of life … the shadows were striking:
Beams now stretch across the entire structure and are ready to take on a roof.
We’ve decided to conduct an experiment:
- The roof on the large room (intended to be dry) will be built using the same standard soft-wood boards.
- The roof on the small room (intended to be a moist room to store root vegetables) will be made of small acacia logs (long-lasting and rot resistant).
And so we embarked on a first-of-its-kind-for-us adventure into our small acacia forest to cut down some trees (while thinning a dense and overgrown forest). I thought I’d seen this car do everything … today it did this:
Tomorrow ad midnight a group of 21 Belgian youth are arriving at our village to spend 8 days with us (that may be more than all the people I’ve met face to face and interacted with during the last year!). If the weather permits (we’ve had a very rainy season), by the time they leave, the roof will be complete and the walls will be covered with an earthen finish and we will be ready for the final burial (so that the structure will no longer be eroded by the elements).
Let’s do this!
After winding down from the full-house weekend … we got back to our “regular schedule”. Marta stayed with us a while longer and helped us get almost to the finish line.
We were excited to finally get to level 21. Here we are passing over the front arch for the first time:
When we finished that wall segment we finally got to pull out the forms … and … it was exhilarating to unveil the self-supporting arches … so simple, powerful (the more we weight we put on it – and we will be putting on quite a bit – the stronger it gets!)and beautiful (I’m really glad we decided to give arches a try!):
Yesterday we finished, with Marta’s, help going all the way around the structure and were left with only with two small segments of the outside wings.
Today Iulia and I went out and completed those two small segments – counting down the last of 6 sacks … and suddenly the the last can is tossed up, the last sack is placed down … the last tamping … earthbag walls were complete!
Fascinating journey from a crater to a structure… made of the same earth we dug out!
We are now waiting to see if we can get the acacia logs we want to make into a roof (our preferred option). If we do, they will be freshly cut and will need some time to cure … meaning that we won’t be able to place them on the structure before winter. If we don’t get the logs we will rever to plan B: regular 2×8 to build a flat roof. That may still happen in the coming weeks.
Depending on the weather we may be able to get some more primary rendering work done … but that is optional … maybe continue with the electrical wiring … I am relieved and satisfied we got this part done … much to share … too tired to do so now.
The day before yesterday we finished level 18. Yesterday we started level 19 by putting in the ventillation pipes (for air flowing out of the two rooms). We cobbed them in place and then continued to work aroud them.
Today we focused on the arch above the entry door … and we started by adding two more arch pieces on each side until we were ready for the last 3 sacks that cap the arch.
… and cap it we did
I am soooo looking forward to taking out the forms … but holding off until we add the final layer on top of the arches 🙂
I thought we would be able to finish with 21 levels … but now that the first arch is complete and the highest point is set it looks like we will need to go up to 22.
Iulia is going away for a few days … after which we hope we will be able to finish before deep frosts settle upon us (temperatures are dropping rapidly).
If all goes well (we will in the coming days) we wil have acacia (strong and rot resistant) logs to cover the entire roof … keeping our fingers crossed that we will be able to close the cellar before winter!
Originally we intended to backfill only once, about half way through and then at the end when we bury the structure. But, the structure is going to be a bit higher then expected and working higher up becomes trickier, especially for two people … so … after finishing level 16 we decided to backfill again.
Work started yesterday when we pulled up the plastic cover and scanned it for tears and wholes. Most of it was in good shape (it got buried in some soil which protected it from the sun). We replaces one section that was torn and brittle.
Florin arrived at 10am and started by clearing a path (we cleared most of it by peeling away soil as we filled the tubes):
He brought soil into the tight corner with the front loader then used the spoon to move / push it into a place:
Then he came around the top of the site and started filling behind the structure
And with a bit of manual labor we the first corner was full
And moving gradually along the wall … until is was all full
… bringing us to the other side which had better access so that the front loader could be used to bring soil in
then we went back around to the first corner (which we left slightly exposed in case we needed to bring in more soil) … and buried it:
… it was done in 3 hours … and now again we get to work at “ground level” … this time all the way to the top:
It is amazing to see how quickly wild grasses and weeds went to work healing the soil around the site … and now, after the excavator, how bare everything looks again … we are already looking forward to bringing in plants to heal the site and help nature take over once again.
We tend give much attention to the growing walls, but we would like to acknowledge the unsung heroes of this project … the cans we toss up the walls to move soil from wheelbarrows into the sacks and tubes. We recently retired the first pair of cans … and here you can see side be side a new can next to a can that has moved ~25 cubic meters of soil (one can at a time!).
My sister, Orit came to visit for a few days and joined us for a few sessions … we now regularly sit on the walls to take in the sunset (horizon rising):
Istvan also visited with us briefly, showed us saturn in his telescope and joined us for a work session:
Liviu and Ana also visited with us and Liviu also joined us for a morning session (we forgot to take a picture … so you’ll have to take my word for it) … and we have finished levels 14 and 15, we are now working on 16 and the arches have started to form:
The arches have started to draw a finish line … the walls will be finished when the arches are complete and one additional level has been layed on top. Right now, my estimate is that 21 levels should get us there … but that will become more clear as we start to move up through the next layers.
We are currently inquiring about two options for a roof … more on that in an upcoming post.
We had one weekend of construction at the beginning of June with the help of Adi and Dan … we got 10 and half of 11 done.
We then paused because of my allergy-period and because we were busy finishing and launching the new Cutia Taranului website. In recent weeks we got back in the saddle, we finished 11 and 12 … and its feeling more and more like a place.
We’ve also put in velcros to which we plan to attach a grain storage and dispenser (planned to hold ~100kg of grains):
Sia, a new puppy who has been with us for a few weeks is getting acquainted with the site … and also has manifested a destructive quality … it seems she enjoyes tearing into earthbags and digging soil out 🙁
Today we started 13 which brought us to the levels of the rectangular door frames …. which means that soon we begin to form the arches on top of the doors.
And finally we have out overall progress indicator. This pile of soil is like an hour-glass … if my calculations were correct it should have enough soil to bring us to completion. When we started construction this year the pile reached out to where the mixer is currently standing so we’ve taken quite a bite out of it. It is nice to feel the space starting to open up and reconnect with the world beyond it.
I estimate we are going to end up with 19 or 20 levels.
And lastly some number I’ve collected:
- We are currently mixing batches with a ration of 4 shovels of sand + 12 shovels of clay soil. This fills an 80 liter wheelbarrow.
- A wheelbarrow is roughly the amount of soil that goes into a sack (1 meter long when flat, 80cm when filled to the max) … though we are using mostly tubes (not sacks).
- Each batch includes 2 wheelbarrows.
- Each wheelbarrow contains ~25 cans (3 liters in a can) … so it takes ~25 tosses to “move” a wheelbarrow of soil up the wall.
- Each batch (of 2 wheelbarrows) translates into ~1.5 linear meters of wall (we are using 50cm wide – when flat – tubes and bags).
- Which means that each can holds about 3 linear centimeters of wall.
- At the current rate Iulia and I (neither of us particularly strong) are doing ~2 linear meters of wall an hour (though we will slow down as we move higher up the wall).
- At this rate we can do a level in 3 or 4 days (we work at most 6 hours a day in two sessions … morning and evening).
We’ve completed levels 8 and 9 …
… on level 9 we were joined by Itsik and Yifat who visited with us for a week … so we reached and celebrated the end of 9 together.
In level 9 we also put in additional vertical reinforcement by pounding in rebars into the longest stretch of buried wall that we have (~6 meters) … and we will continue to do that in an interlaced pattern to give the wall some more strength to resist the weight of the earth piling up behind it.
Which brings us to today … soil … we called the excavator back (marking what is probably the half-way point of wall construction) … to start backfilling and bringing some more soil to our mixing station (so that I don’t need to carry it in a wheelbarrow). Yesterday we prepared by pulling the plastic covering over the walls
.. and so it started … and very quickly the corner behind the first retaining wall was filled up ….
… during the backfilling, a new soil pile near the mixing station started to appear
… and before you know it (almost three hours later) the backfilling was complete …. so from the outside we are back at ground level (which does make some maneuvering on the walls easier)
… and a huge pile of soil (30+ cubic meters) is now blocking the entrance and hiding the site … when that soil is gone, construction of the walls should be complete (or very close to completion)
As the work progressed we realized we were going through A LOT (= surprising amount) of soil … we’ve used up most of the free soil on and around the site … and it doesn’t look like what we have left will be enogh to complete backfilling and covering the structure. At first this felt like a potential problem … but it quickly transformed into opportunity. It looks like the supply of soil needed to complete this project will overlap and lead into the next project. One option weve been discussing is a small lake (a whole other story). Another option is to start excavating what may be the next construction project … either way … it left us with a pleasant sense of continuity 🙂
Before presenting some highlights I would add that there are a few details which, to my understanding are only correct in the context of typical above ground houses, less so with bermed or underground structures.
“At present, there are over 15,000 Earthbag buildings worldwide with recent Earthbag constructions gaining approval under strict US building codes.
An estimated 55 Earthbag structures built in Nepal survived the 2015 earthquake, in regions ranging from Solokumbu to Sindhupalchok to Kathmandu.
… The main material of an Earthbag structure is ordinary soil obtainable at the worksite.
… A study by the U.S. Federal Highway Administration found that the half -life of polypropylene fabrics in benign environments can be 500 years or more. The
bags themselves have a tensile strength even higher than that of steel, and can resist circumferential forces generated from the weight above.
… An Earthbag building uses its own weight to anchor itself to the rubble trench foundation. Since the superstructure is not attached to the foundation by bolts or rebars, the foundation and the
superstructure are able to move independently minimizing the shock transfer to the walls. A rubble trench is also built of individual units rather than a continuous beam further absorbing the shock.
Earthbags are resilient. As per an experimental study on vibration reduction … Earthbags have a relatively high damping ratio with horizontal as well as well as vertical vibrations effectively reduced.
… All of these components make Earthbag structures extremely earthquake-resistant. Tests done in accordance with IBC standards have found that Earthbag construction far exceeds Zone 4 standards, devised to protect against the very highest level of seismic activity. Numerous Earthbag structures have been built in the United States. Earthbag structures are permitted by the California Building Code, the toughest in the United States due to high seismic activity.”