In addition to dRain Joint, I also noticed this 100% recycled-content board called NewWood at the National Green Building Conference & Expo in Salt Lake City. The “wood” is actually a composite of recycled plastic and recycled wood that is locally sourced and manufactured in Elma, Washington.
The company behind the product says NewWood can stand up to any condition (i.e., heat, rain, freeze cycles). According to a marketing pamphlet, NewWood is more impact resistant and absorbs less water than OSB, hardboard, and fiber cement, based on testing.
NewWood can be nailed and cut and is available in 4′x8′ sheets in 7/16″ thickness. At this size, a sheet weighs 60.5 pounds. NewWood has various potential uses and the start-up that makes it suggests trying the product as underlayment, utility board, backer board, and in landscape applications. A version for fencing will be available later this summer.