E-NEWS has reported on these concrete tents in the past and we just came across this latest offering. According to the manufacturer, The Concrete Canvas Shelter is a large inflatable tent made from a canvas-like fabric that’s flexible and lightweight. However, when water is added to the material, it hardens into concrete. The tent was created by a U.K.-based company, which was originally developed for military use and also in an event of a natural disaster where sturdy shelters need to be resurrected quickly (admit it, though - you're thinking it might be the perfect way to remove those 20-something offspring from your house).