Take my word for it, this giant mud-grey bubble is more interesting than it looks. It’s made of Concrete Canvas, a flexible textile that takes on the attributes of concrete when soaked with water. The material allows permanent structures to be put up in hours instead of days, by just two men (with the right equipment). The video shows how it’s done, in four easy steps. Funny thing is, they can make concrete cloth, but they can’t make a truly iron-free shirt.