Nakatombetsu Earthbag Project
Stage 6: Installing Arch Forms
The arch forms are installed on top of spacers set, unfixed, on top of the box forms. The are shimmed plum but are only held Ray Ban Sunglasses Ray Ban Sunglasses strong> in place by the pressure of the bags around them.
Note the Ray Ban Sunglasses depth of the arch forms is the same as the box forms. This is because they must provide both an arch surface for the vertical door/wind Ray Ban Sunglasses ow wall on the outside, and an arch surface for the dome as it begins to close in.
A close up view of the door form.
Here is a model of what the dome is supposed to look like when the bag work and plaster is all finished. This gives a clearer idea of how the door and window openings will look like. The final structure will end up having slightly more extended openings as we decided to add a little more mass than the initial design. Looking back, it was probably was not necessary but this is an experiment after all.
When using unstabilized soil, using fanbags around the arches is probably the strongest construction method. To make fanbags, a box form was used where the bag was filled and tamped completely, and then set in place on the structure. Fanbags are not as heavy as a regular bag. And, being that they are solid makes them easy to maneuver. If possible, it is recommended that one makes the fan bags on the structure. In our case, however, the dimensions of the structure were small enough that it made more sense to mass produce these on the ground while other work was being done on the wall.
Two fanbags have been set in place around the window. Note the continued use of the lathe, wrapped around each layer.
A view of the first fanbags from above.
The bagwork continues. Openings in the domed part of the wall are technically challenging. But they sure look cool as they come together.
Because of the dome wall getting smaller, the number of fanbags increases. Note the gaps in between the fanbags. These irregular openings are filled by setting a bag directly in the gap and filliing and tamping to shape.
Now, the keystone bags begin. Just like a brick or stone arch, the keystones are what keeps it all together. These are hand shaped directly in place, three bags at a time, up on the wall.
Tada! There you have it. The inside keystones of both windows were finished first allowing for the dome wall to be continued independent of the outer keystone work.