Special Report: TROUBLES WITH SYNTHETIC STUCCO A state-funded study found a pattern of cracking, water penetration, and delaminated sheathing by Richard Piper Soft-coat synthetic-stucco systems typically consist of (from the outside in): a thin polymer-based surface coat, fiberglass mesh embedded in a base coat of portland-cement and polymer, expanded polystyrene insulation, adhesive, and substrate. The most common substrate is gypsum sheathing, which is highly vulnerable to water damage. Exterior insulation finish systems (EIFS), also called "synthetic stucco," have been used more extensively on commercial construction than residential (see "Synthetic Stucco and Insulation Systems," 6/87). While their use continues to increase, there are no product standards other than the manufacturers' and very little testing has been done other than by the manufacturers. The majority of the testing