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Construction Earthbags

Earthbag Cellar – Ventilation Chimney

This seemingly small part of the project turned out to be a place where I immersed myself more than I expected.

The initial objective was to protect the ventilation exhaust pipes from sun (they are made of plastic), rain and rodents. But as it came into being I felt it was a surprisingly prominent aesthetic element  that invited me to give it more attention.

I was not able to give this all the attention and quality I wanted because of numerous constraints, especially, in this case, the position of the pipes makes it difficult/precarious to reach.

The first step was to build forms in place (no pictures) and to pour a concrete base.

The next step was to build a brick chimney. I felt comfortable with bricklaying from my experience with rocket stoves. I did experiment with a new (to me) mortar mix (1 lime : 1 concrete : 6 sand).  I quickly gave up on trying to lay the bricks  perfectly  level because of the limited access to the work. I tried to incorporate some anchoring mechanisms into the chimney.

Then it was off to figure out how to design, build and install the head of the chimney. Originally I wanted to create a triangle-shaped roof. But as the chimney came up and took on character in relationship to the cellar, that felt wrong. A more soft and round form appeared in my mind and I set out to draw it … make cutting templates … and finally into the workshop to make it.

First came the base:

… and on top of it … the arch form I envisioned.

After a dry-assembly failed I made a change that would make assembly of the two parts easier … then it was off to char and oil all the wood surfaces:

Next was partially fixing the wire mesh onto the base:

… and initially assembly of the base (to get a sense of progress and make space in the workshop):

Then came the metal-roof preparation. First measuring real sizes and cutting the sheet to size and bending it. I’ve got a slightly tedious but fairly reliable strategy for bending:

In reality it was a sequence of bending and cutting actions that led to a sheet that could be bent and folded onto the curved arch.

… and then mounting it and nailing down the mesh and:

I am not confident that my anchoring strategy has worked ou well … so we will see if this thing holds in high winds or if it will need some reworking next spring!

Tomorrow we hope to get some wood boards that I need for working on the front door … and the earth-floor has set enough that we can carefully walk on it … so it may be possible to also approach the inner door and shelves (without putting them in place yet) … so that when the floor does set we’ll be ready to go!

Categories
Construction Earthbags

Earthbag Cellar – Structure Done(-ish)

When I thought I’d finished with the internal walls I decided to play around with some of the cracks by filling them with clay-slip. What started out with a small local (small spot) experiment became another layer of finishing on all the walls. In the small room (sorry no pictures!) that experiment was expanded to include colors using metal oxides (readily available in our village shop). Though the colors are visible, I expect they will change drastically as the underlying clay substrate dries and becomes much lighter.

We are running a fan that is circulating air (and pulling humidity out of the small room).

With that done (ish – I expect another round of work with the cracks when the walls set … again because I am curious to see what kind of results we can expect with the clay soil under our feet!) I started alternating between a finishing layer on the earthen floor and experimenting for the first time with a lime-based finished for the external and retaining walls. It was interesting working with the lime but only time will tell about the results. Though the work is done, the walls still need to be uncovered (they are covered with tarps) and watered once or twice a day for around two weeks (the time it supposedly takes the lime finish to set).

This is what it looks like now (under the unfairly glorious light of a sunset). The walls turned out grey (and will probably be painted a tan color with a lime-wash in the coming days).

I decided to use the typical lime available in hardware stores. The quality of this material is questionable. Ideally I would have liked to use  aged lime-putty which I know who to ask to try go get – but that is not as easily available. So in the spirit of experimentation (that permeates this entire project) I went simple and local first (and that is just one of many variables that can effect the quality of the lime-based work). If that fails ( = does not survive the elements) it may need to be redone!

Though the work is “done” … it isn’t really. In the coming days I hope to be able to burnish the floor (make it a smoother finish), water the walls … and get started with working on the outer door.

I am curious to see if the floor sets hard enough soon enough (the walls can take their time) to be able to move our food in for this winter!