This paper discusses practical challenges and case studies involving field-applied and factory-applied sealants. We have substantial experience selecting and specifying sealants for exterior wall applications, reviewing substrate preparation and sealant installation work in progress, investigating problematic sealant conditions, and reviewing industry standards. It is our experience that poor sealant selection, inadequate substrate preparation, and faulty installation work are rampant in the field of construction sealants used in building enclosure installation and rehabilitation projects. Despite helpful industry standards, manufacturers’ literature, and widely known best practices, the sealant selection, testing, installation, and quality-control processes are frequently rushed and poorly performed. We discuss various successful and unsuccessful projects, with an emphasis on common problems, lessons learned, and realistic good-practice suggestions that can help minimize risks of similar problems occurring in the future.