Oak is a durable hardwood with a distinctive light-colored look that appears grainy with yellow rays and flecks. Oak is also very resilient against water damage, warping, or mold. Oak has been used for thousands of years as a hardwood, however, it can take up to 150 years before an Oak tree is harvested and ready for use. Oak is the most commonly used hardwood and is used for flooring, cabinetry, furniture, and construction.