When selecting wood for an outdoor bench that will see heavy daily use, durability isn't just a preference—it's a necessity. The champion in this category is undeniably Ipe (Brazilian Walnut). This incredibly dense tropical hardwood is naturally resistant to rot, insects, and moisture. It's so resilient that it often outlasts the hardware used to build the bench, earning a Class A fire rating similar to concrete. While its hardness makes it challenging to work with, its longevity of 25+ years with minimal care is unmatched.
Close contenders include Teak, renowned for its natural oils that repel water and pests, offering a classic look and 20+ year lifespan. Shorea (Philippine Mahogany) is a more affordable tropical alternative with good durability. For a domestic option, White Oak with its closed cellular structure provides excellent rot resistance, while Western Red Cedar and Redwood offer natural decay resistance and are easier to work with, though slightly softer.
The key to longevity lies in the wood's natural oils and density. For maximum durability, always use stainless steel or galvanized fasteners and consider a periodic application of a UV-inhibiting oil for woods like Ipe to prevent silvery graying. Your choice ultimately balances supreme durability, maintenance tolerance, budget, and environmental considerations.