Cedar wood contains natural oils, particularly cedar oil, which gives the wood its distinct aroma. These oils have inherent properties that make cedar resistant to decay and rot. The oils act as a natural barrier against moisture, preventing water from penetrating deep into the wood fibers, which is a common cause of decay in other types of wood.

Cedar’s natural oils also act as a deterrent to many types of insects, including termites, ants, and beetles. These insects are less likely to infest cedar wood compared to other, less naturally resistant woods. This makes cedar a popular choice for outdoor decks where insect damage is a concern.