Lightweight Green Pavers. Vast's Composite Pavers are made almost entirely from recycled materials - mostly scrap tires and plastic bottles - and weigh one-third as much as traditional brick or concrete. They come in 4-by-8-inch and 3-by-6-inch sizes and are installed over a grid base that takes the guesswork out of alignment. (The larger size can be combined with an open-graded base for a permeable surface.) Material costs for the pavers and the 16-inch-square grids run about $5 per square foot. Vast Enterprises, 612/234-8958, vastpavers.com.