Rowly -
How big of a structure are you looking to build with the tires? I used wire and decking screws to hold the 'groupings' together.
Using the largest tires I could find (Which happen to be pickup, dumptruck and backhoe tires), I lined up a bunch of them in a row, sidewall to sidewall after drilling holes in all of them to ensure no air would be trapped. Then I ran 2x4's along the sides and used decking screws to secure the boards to the tires (The tread portion in this case), creating a long tube type of structure. Then I screwed more tires to each side of the 'tube' with the sidewall facing in. Then using more screws and wire I attached random pieces of metal, smaller spare tires and tree branches to the 'structure' to fill it out. You could make similar items by connecting a row of tires together sidewall to sidewall to make a 6 foot or greater length, then attach 4 more tires to the side of the connected ones making a pseudo automobile/rolling sausage shape.
Owner/Builder of Ottawa Canada's first official off-grid home.
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