Is “greenboard” a suitable substrate for Sto EIFS?
No, gypsum wallboard in compliance with ASTM C 630, often referred to as greenboard because it has a green paper facing on one side is an interior wallboard commonly used in wet areas such as bathrooms. The only suitable gypsum board substrates for EIFS are Gypsum Sheathing in compliance with ASTM C 79 and Glass Mat Faced Gypsum Sheathing in compliance with ASTM C 1177, for example, Dens-Glass Gold(R). The sheathing manufacturers instructions should be followed with respect to handling and attachment of the boards and the applicable EIFS code compliance report should be followed for any special attachment requirements to satisfy wind load conditions.
