A curtain wall is an external non-structural building component that is designed to hang down from the floor slab of a building to the floor below (similar to an actual curtain, as the name suggests). Aside from creating an attractive exterior aesthetic to a building, the primary functions of the curtain wall is to provide a weather barrier against water and air infiltration and for light transmittance to the interior space.
A systematic investigative approach should be used in exploring any leak, but more importantly in curtain wall systems.
An investigation of curtain wall failures typically involves the following steps:
1. Identification of symptoms and understanding the problem: This is usually uncovered during the discovery process. Does the leak happen every time it rains or only during wind-driven rains? How long has it occurred and where do you see the leak coming from? – These are typical questions that are asked during our investigation that are aimed at understanding issues with the system.
2. Review the original design intent: Access to original design documents and shop drawings are worth their weight in gold in this step; though it is often than not unavailable in older buildings. Understanding the way the curtain wall is originally designed is crucial in understanding the cause of leaks.
3. Verification of as-built condition: Even though the design intent may be perfect, it is rarely the case to have as-built conditions match the design documents 100%. As-built drawings may show deviations between design documents and as-built conditions. If such drawings are not available, probes may be used to investigate the as-built conditions of the system.
4. Documentation of current condition: As the building ages and is exposed to the elements, components may deteriorate and no longer serve their function. Accurate documentation of the current conditions is necessary for the investigation process.
5. Identification of potential causes of failure: Once the original design, as-built conditions, and current conditions are documented, a potential cause of failure could be formulated. Were there differences between the original design and the as-built conditions that led to the failure? Were there deteriorated components that contributed to the demise of the system?
6. Testing of the system: Destructive and non-destructive tests may be employed to test our hypothesis and cause of failure.
7. Implementation, evaluation, and testing of trial repairs: Once the cause of the leak has been determined, trial repairs may be performed to determine its efficacy in addressing the leak.
Often times leaks in curtain wall systems are challenging to address since they can occur anywhere along the wall. In addition, the system is often complex, with multiple layers of glass and aluminum, which can make it difficult to access the source of the leak. Additionally, the weight of the glass and aluminum can make it difficult to remove and replace damaged components, which can make repairs challenging. It is important to employ a systematic approach to investigation to fully understand the issue at hand.
If you’re facing a challenging leak in your window system and would like advice on a solution, contact Rimkus today!