We finished filling and tamping the second level of tires this morning, and this afternoon we poured the concrete half tires and spacers on the second level.
The last five days have been busy as we charged ahead packing and filling tires. Our best day so far is over thirty tires packed, and we have been averaging around twenty.
The packer works well. With one person operating the packer, and one person supplying dirt we can get a lot of tires filled. A third (and sometimes 4th) person follows behind the packer crew filling and tamping the centres of the tires that have just been packed. One of the welds did break on the packer and I re-welded the joint that evening (hopefully better).
We are definitely finding that no two tires are the same, particularly when made by different manufacturers. Add in variations in remaining tire tread and sidewall condition and our ‘bricks’ have minor variations in height and wall coverage. Not a huge deal but you do have to take time levelling and matching adjacent tires. For the next round there are a few spots where I may use slightly thicker or thinner tires to adjust for these variations.
Yesterday afternoon we started preparing for pouring the concrete half blocks. We started by laying wire mesh around the location of the half block. The mesh is attached to the surrounding tires using 2″ roofing nails. We also used tin roofing screws (because I have some leftover from other jobs), and these were very effective in securing the mesh. We also attached a hay wire tie from the mesh to the tire to help strengthen the mesh while the concrete was being poured and curing.
We actually poured our first half tire yesterday evening. Just as we were finishing the pour we got caught in a rain storm and had to get everything put away and covered for the night. To make matters worse the storm knocked out the electrical power and we did not have any water pressure while cleaning up. BC Hydro did not get power restored until around 10:30 am today. Breakfast was poached eggs and toast on the barbecue, and we started packing tires in the morning using the generator. Incentive to get the earthship done and off the electrical grid!
We poured the concrete using a portable mixer, screened gravel/sand off the site, and portland cement (3/4/5 ratio).
We added engineered fibres to each batch of concrete to increase the tensile strength of the concrete.
By the end of the day this is what the site looked like!
More detailed photos and captions courtesy of Sandra.
Concrete 1/2 block forms using mesh.
Here’s Sean finishing up a mesh form.
Filling the second row of tires: Line with cardboard (and plastic if rainy/wet) fill with dirt, same ole, same ole!!! As many others have discovered before us, getting a perfect cardboard circle is not only difficult, it is hard to stuff in the tire! We consulted the book and started shoving two rectangles in the hole. In the rain and dampness we used thin, used lumber wrap to line the cardboard, otherwise the cardboard was soaking through before we could compact the tire.
Here’s Stephen in the blue jacket filling a second row tire!