Case 5
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Cause of Defects
For aesthetics reasons, expansion joints are sometimes inclined or curved to break the monotony of the facade. However, the inadequacy of the joints in containing and channelling runoff off the façade causes runoff to overflow the inclined or curved joints vertically downwards and causes vertical stain streaks to appear on façade panels and even on glazing. The vertical stain streaks will usually originate from an intersection point of the joints. Such points act as an obstruction for the flow of runoff within the joint and cause the runoff to be misplaced and to overflow the joint (Figure 1).
Consequences
Stain streaks that form due to misalignment of joints are especially noticeable since they form away from the joints. Stains should be cleaned off periodically to prevent long-term accumulation which could be difficult and expensive to remove later.