The multi-component Exterior Insulation Finish Systems (EIFS) designed nearly 30 years ago are still the basis for today's EIFS. However, over the years new EIFS have been developed to meet the needs of the building industry. One such system, EIFS with drainage, incorporates the components of the basic barrier EIFS, but adds the dimension of a drainage plane behind the insulation board. One EIFS with drainage system consists of a liquid coating that can be used as a flexible weather resistive barrier in place of building paper, and as an adhesive in place of the metal fasteners
This paper describes the testing and selected performance characteristics of one component of EIFS with drainage, an acrylic polymer-based coating that trowels easily, forms breathable, highly water resistant weather barrier assemblies, and adheres the insulation board to the typical EIFS sheathings, all in one step. Early grab, or “green strength”, helps hold the insulation board when it is first set in place, which may allow the insulation board to be rasped sooner than when a more conventional liquid adhesive is used.
Full component testing of the EIFS, including joint-treatment and flashing requirements, is not the objective of this paper.