The Importance of Destructive Testing for Identifying Concealed Resultant Structural Damage

Defects in a building’s water-resistive barrier (WRB) and veneer drainage systems are in direct conflict with modern building codes, industry standards, and manufacturers’ instructions and create avenues for water intrusion and/or the accumulation of moisture within the building envelope system. The effects of the damage resulting from these defects are not always readily apparent and are often concealed in the form of deterioration of the structural sheathing and framing systems. Moisture intrusion through the building envelope and deficient discharge of the moisture from the veneer drainage system may result in moisture distress to the structural framing over time, ranging from latent to severe and unsafe conditions. The authors have investigated hundreds of water intrusion cases and have found over the course of these investigations that evidence of the moisture intrusion and damage to the structural systems may not be revealed by distress at the interior finishes or manifested at the exterior façade. The lack of reliable correlation between exterior and interior distress and framing deterioration necessitates the removal of exterior finishes to determine the condition of the structural framing. This paper is case study-driven and provides examples of both positive and negative correlation between visible interior and exterior distress and the extent of underlying structural damage observed through destructive testing.