Exterior Insulation Finishing System Stucco does not rely on a hard base coat but instead is thinner layers of modified materials that make up the EIFS cladding. Each manufacturer has their own special system having small differences between layers however, the fundamentals are essentially the same. Typical EIFS Systems are composed of an adhesive on the substrate, foam insulation board, a base coat containing mesh fibre for strength, and a finish coat designed to keep out water. If desired, you can also add an additional moisture barrier layer to the substrate.