Barrier EIFS Clad Walls: Results from a Moisture Engineering Study

Abstract

This paper presents the results of work performed to enhance understanding of water penetration and moisture characteristics of barrier Exterior Insulation Finish Systems (EIFS) clad walls. The investigation was prompted by recent failures of barrier EIFS clad walls on houses in the Wilmington, North Caro lina area. The objective was to determine the cause of the problem and gain a better understanding of water penetration and moisture transport in these systems. The study included a field investigation, laboratory experiments, and computer simulation. The experimental results indicate that barrier EIFS clad walls are prone to leak in areas around penetrations and allow water to enter into the wall cavity. A drainage cavity wall was also tested, and observed to perform well, managing water around penetrations and preventing leakage into the wall cavity. The computer simulation indicates that barrier EIFS clad walls in Wilmington have low moisture tolerance due to slow drying rates. In conclusion, barrier EIFS clad walls do not provide effective management of rain penetration. As such, in-service performance is unpredictable and unreliable. In con trast to barrier EIFS clad walls, walls using a drained cavity approach were shown to provide good control of rain penetration.