SLIDESHOW: Living plants out-last, out-perform roof shingles

The 7/12 pitch (7 feet of rise in 12 linear feet) is the steepest roof where the mesh and soil-medium system can be used, according to the supplier: Resource Conservation Technology (www.conservationtechnology.com) of Baltimore. Anti-slip cleats, or bananas, made from recycled ABS plastic, hold the porous growing medium for the roof vegetation.