For instance, NR employed a timber consultant and tried out different hardwoods before settling on Forest Stewardship Council (FSC)-certified greenheart from Guyana. "Greenheart has a long track record of use in challenging applications," Bartlett says. "It's so naturally durable that it won't require maintenance - it has a design life of 30 years and can last 60. Preservative treatment is unnecessary - it's resistant to attack by shipworm and wood rotting fungi.
Source: wiktionary