Is cypress a good wood for outdoors?
In short, there are better choices…. When cypress trees were harvested in the late 1800’s to early 1900’s, the trees were extremely mature, having stood for hundreds, sometimes thousands of years. Known as “old-growth cypress,” these trees were heavy with heartwood and had developed a distinctive, oily substance in the wood called cypressene. Cypressene acts as a natural preservative, making old growth heartwood extremely resistant to decay and insect attack. This is how cypress earned the reputation of being so good for outdoor use. In fact, even when left untreated, old growth cypress can last for decades.
Then there is the cypress of today… Known as Second Growth Cypress, trees of today are harvested at a much younger state—less than 50 years. The trees grow quickly during their early development, contain a large amount of sapwood and lack the presence of cypressene. For this reason, today’s cypress does not have the same fortitude for outdoor use. In fact, you may expect to get 5 to 7 years of service.
What are some other options? In affordable hardwoods, white oak and sipo mahogany are popular choices. Both woods are often used in marine projects due to their resilience. In the US, black locust has excellent, natural decay resistance, though the wood is often short and spindly. Teak is widely known for it’s resistance as well. It’s easy to work with, however, due to it’s high oil content, regular wood glue will not hold a joint. Use epoxy! Plantation teak has made the wood much more affordable, though it is said to be not quite as durable as native teak. Tropical hardwoods such as ipe or cumaru are frequently used for outdoor decking. Both woods are incredibly dense, making them hard on tools. From personal experience, even just trying to drill pilot holes through the wood proved quite frustrating. But that’s the price you pay when seeking wood that can stand up to mother nature!