Part our design process was trying to figure out how many bottles we would need to collect and wash. To do this, you need to know which bottles you have access to. We chose the bottle that we thought we would be able to collect the most of. We then measured the diameter of the bottle and estimated the amount of space between each bottle for the length and the height. To get the calculation we subtracted the area of the door, window, and pillars. We estimated about 500 bottles for our front wall. We also decided to use two different bottles – one smaller and one larger. The smaller one would be used between the top two pillows in a design and would be structurally separated from the large bottles so it would be okay to use this different size.
Washing bottles is time consuming and is best with a small group of people. The reason that bottle washing is important is because if there is organic matter (like labels) inside the structure it will rot and smell. What we did when we washed the bottles was set up a few bins, one for washing with soap, a second for rinsing, and a third for the removed labels. We soaked the bottles with soap for ten minutes or so before scraping of the labels with a steel sponge. Often times if the bottles are old there is mold or dirt on the inside of the bottle that cannot be removed from washing and rinsing. To get at these spots, we got wire and attached yak fur to scrub the bottoms or sides of the bottles.
The bottles should also be completely dried before they are placed on the structure so it may be best to wash them and dry them ahead of time. Don’t forget to only clean the bottles that you can use or separate different sizes of bottles so that when the labels are removed you don’t accidentally use a slightly different bottle when building.
We couldn’t wash the bottles up our construction site because we did not have running water so we washed them elsewhere and transported them using a van.
Laying the Bottles:
We had planned on laying the bottles so that they were flush in the front by using a wooden plank. We ended up just doing it to eye. One person would stand on the backside of the wall and the other person would stand on the front side of the wall. We placed the bottles flat over a layer of mud, with the first layer starting with a layer of mortar over brick. Then we would put the mortar on top of the second later so that the gap between the two bottles would be filled. Keeping the bottles straight and flush with the wall was difficult. Sometimes it was easiest to readjust and make sure they were in line after one day of drying.
On our largest wall face we had placed all of the layers of bottles in one day. When we came back the next day the wall was drooping forward and it took about an hour to get it all back together. The lesson that we took from this was to not place bottle layers too high at once. Five to six layers should be at least partially dry before adding on more layers of bottles. Once the mortar is slightly dry the wall will begin to crack slightly. Just fill in the gaps with more mortar every time you see cracks.
On the bottle necks on the inside of the space, we crisscrossed a wire to support the placement of the bottles. As I said earlier, we decided to fill the interior wall completely with mortar. This is quick and easy. Just fill in the mud until the entire bottleneck is covered, making sure that there are no air pockets within the wall. If you use wire to support the bottlenecks you can just leave the wire covered and inside of the walls. After this we used a second layer ‘plaster’ which is a special white soil with a small amount of yak dung.