Mass timber is a growing construction trend in North America and offers many unique opportunities for the North American forest economy. There are many forms of mass timber ranging from glued laminated beams used in heavy construction to cross laminated timber, which provides feed stocks for tall wood buildings, all of which need additional care when exposed to excess moisture or ground contact. As with any wooden construction material, careful planning and design are fundamental to maximize service life and ensure safety of mass timber construction. Material durability has been identified as a key concern of early adopters and code specifiers. As construction trends flow into more subtropical regions, adequate information on the expected service life of mass timber and effective protection strategies are of the utmost importance. USDA Forest Service researchers at the agency's Forest Products Laboratory are central to ongoing laboratory and field evaluations of mass timber durability, including termite resistance, fungal decay resistance, coatings for interior and exterior application, and potential treatment options for mass timber. Thus far, completed tests do not support the current thought of mass timber as a naturally durable material and future work will focus on finding safe, yet effective treatments that can maximize service life and minimize the actions of biodegradative organisms.