The list of acceptable substrates for each type of EIFS can be found in a system’s respective test report to CAN/ULC-S716.1, “Standard for Exterior Insulation and Finish Systems (EIFS) – Materials and Systems”; however, the following substrates are generally considered acceptable:
- minimum 11 mm thick exposure 1 OSB classified as PS2 exterior wall sheathing
- minimum 11 mm thick exterior-rated plywood sheathing
- minimum 12.7 mm thick exterior gypsum sheathing conforming to ASTM C1177 / C1177M, “Standard Specification for Glass Mat Gypsum Substrate for Use as Sheathing”
- cementitious panels
- fibre-cement panels
- concrete block
- clay masonry
- cast-in-place concrete Note that, in some cases, the list of acceptable substrates may be limited by the EIFS manufacturer.