9.3.4 Protective-coating selection considerations—A coating or insulation system can be applied to the installed FRP system to protect it from exposure to certain environmental conditions (Bisby et al. 2005a; Williams et al. 2006). The thickness and type of coating should be selected based on the requirements of the composite repair; resistance to environmental effects such as moisture, salt water, temperature extremes, fire, impact, and UV exposure; resistance to sitespecific effects; and resistance to vandalism. Coatings are relied on to retard the degradation of the mechanical properties Table 9.1—Environmental reduction factor for various FRP systems and exposure conditions