Measured pressure equalized performance of an exterior insulation finish system (EIFS) specimen.

Describes a research and development project that has been started in order to generate design guidelines for PER walls. The three tasks covered are computer modelling, experimental evaluation and development of design guidelines. Describes the results of the experimental evaluation of an exterior insulation finish system. The systems were evaluated for air leakage characteristics, pressure equalization response and water penetration. Concludes that a wall designed to PER principles is more able to resist rain penetration. However, as the pressure equalization response is poorer further from the vent locations, it is important to carefully consider the position and spacing of the vent locations in the design of the wall. The results showed that some flaws in the air barrier may not significantly impact the amount of rain penetration; but, defects in the rainscreen can have significant effects. These results suggested that guidelines should be determined for the optimum spacing of vents and joints in the EIFS wall.