We’re leaving Tumán! This was planned since a long time, so we have carefully prepared everything for Manuel and Eric to be able to continue with the work. Our goal to finish the strawbale walls and most of the earth plaster has been reached, but we still spent the last day working as much as we could.

The front facade is finished, just needing a bit of smaller aesthetic adjustments, but we came up with the idea of leaving behind two pieces of the wall as a sample of the level that we want.

The back wall is half-finished and above is our finishing sample, polished into perfection by Alondra. The connection with the wood is a smooth, rounded corner.

The exterior screen is fairly simple to finish, now that we have decided the density of the branches, and connection details to the wall behind.

First, Manuel has to reinforce the floor structure with occasional beams, as the dimensions were too weak for the quality of wood that we ordered.

Completion is planned for end of May, and sadly we will have to wait until 2016 until we can see the building finished! We will continue to update the blog, but less regularly than before. It has been a fantastic adventure, and our knowledge about this building technique has improved beyond our expectations!

It’s incredible how much earth goes into the plaster. Suddenly it seems like 13 m³ isn’t that much (but it will certainly be enough) We have also built up a routine with continuous production of clay. Since the earth has chunks in it, we need to soak it for a bit, then work it with our feet. This is time-consuming, so we need to end each day with filling up the pool with more earth, and refill it again at noon.

Another experiment: painting the wooden plinths and “polishing” the walls with a mix of cactus jelly, water and earth. The interior walls will get a coating of lime render, and so we need to get a smoother surface. By rubbing them with a sponge soaked in the mix, we got a better result.

The exterior walls are drying slowly. Even with the warm autumn weather, it takes more than a week in the shadow. Yes, cracks have appeared in them, but not too many…

Meanwhile, we’re busy with the interior walls, which is a lot of work considering all the junctions between the door and window frames and the earth plaster. This is where the difficulty of using a metal mesh shows itself, since the edges are very sharp and easily rips hands and gloves. We are not 100% convinced of some details (mostly a result of the fact that the bales were slightly smaller than expected), but that happens in almost every project!

However, applying the second layer has been very easy, and we have gotten some extra help from Hugo, who knows a thing or two about earth plastering already.

Finally we have a concrete mixer on the site and today we could start producing the plaster for the second layer. The clay turned out to be a bit more sandy than our earlier sample, so we had to adjust the proportions to 2 parts clay, 2 parts black sand, 1 part straw and a special ingredient: after a week in the sun, the cactus/water-mix has transformed into a foul-smelling, green, slimy jelly. But it helps to make a sticky and more waterproof plaster.

In comparison with first layer, application is easy, and can be done in a very thick layer. Mostly, earth is plastered very smooth, but we are very happy with the roughness as seen above.

It’s easter, but we spent the weekend on site, and have placed the last strawbale at last. At each main beam we will eventually place a separation wall, so the interior will not be as open as in the photo above. Meanwhile, we have also been applying the first, thin, layer consisting only of clay and water.

Somehow no book about strawbale construction mentions how to solve the intersection between a sloping roof and the wall. How do you make the strawbales thinner? In our case, we managed with several 90° rotated bales on top, to get bales of different heights.

There are different opinions about the need for a mesh on strawbales, and so we postponed our decision to use this element to the very last day, just as we were going to apply the first thin – “key coat” – plasterwork.

The disadvantage with any metal in the wall is that it might form condensation inside the bale, which affects its stability. On the other hand, the mesh keeps loose pieces of straw from falling out when applying the thick – “base coat” – layer, and can act as a shear force stabilizer of the whole wall.

Considering the warm climate and earthquake risk in Chile, we eventually decided to attach a mesh with staples and home-made pins.

Every day it seems like we are reaching a new stage in the project. Above, we’re dissolving pieces of earth in our own pool built from strawbales and a plastic sheet. It looks like this earth has a bit more sand than our previous sample, which might be good!

We waited 24 hours, but some pieces of clay were still so hard that they needed to be broken with a tool. (Obviously, it would have been better to do this before soaking them!) After stirring the mix with hands and feet we got a smooth cream-like plaster. A simple way to test the ratio of the earth / water mix is to just dip your hand in it. If it forms an even “glove” around your hand, it’s good.

This is what our house is looking like, two weeks before leaving the building site. Before that we plan to apply two coats of mud, key coat and second coat, since we want a rough finish, with visible straw fibers.

The eucalyptus screen is becoming very beautiful after we tried different spacing between the branches. It’s just enough to be able to see the landscape through the screen, but still protect against rain and wind.

From Coloro’s workshop we learned that cactus can be used to make the mud mix more resistant and a bit waterproof. There are many ingredients you can add to your mix to make it stronger, for example: caseina (milk protein), cow’s excrement, linaza oil, cactus slime and so on… Basically choose from what you find around your plot.

So we did, went to the neighbour’s house and asked her for 6 paletas – cactus leaves. Don’t try to cut them without thick gloves!

Then you take the surface thorns away and slice them in 3cm pieces. We soaked them in a 100lt tank and let it rest for a week,
stirring it twice a day. We noticed immediately that the water became thicker and slimy.