The efficiency and service of insulation is directly dependent upon its protection from moisture entry and mechanical and chemical damage. Choices of jacketing and finish materials are based upon the mechanical, chemical, thermal, and moisture conditions of the installation, as well as cost and appearance requirements. Protective coverings are divided into six functional types:
• Weather Barriers
• Vapor Barriers
• Mechanical Abuse Coverings
• Corrosion and Fire-Resistant Coverings
• Appearance Coverings and Finishes
• Hygienic Coverings