1.1 ,This practice covers the minimum requirements and procedures for field or prefabricated application of Class PI Exterior Insulation and Finish Systems (EIFS). Class PI EIFS are systems applied over polyisocyanurate insulation board, in which the base coat ranges from not less than ¹/₁₆ ,in. (1.6 mm) to ¹/₄ ,in. (6.4 mm) in dry thickness, depending upon the number of nonmetallic reinforcing mesh layers encapsulated in the base coat. The base coat is then covered with a finish coat of various thickness in a variety of textures and colors. The insulation board shall be applied over a substrate or over open framing.