Case 5
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Cause of Defects
Rain water could have penetrated through the joints between the window and frame or frame and wall due to sealant failure. Gaps may have also occurred in the glazing groove at the edge of glass resulting from a failure of sealant or if the glass was cracked.
Rain water may have penetrated into the building through the cladding panel joints at parapet wall where the sealant has failed. The rain water then followed along the parapet wall inside, up to the window level and seeped into the room from the sides of the window.
Water penetration may have occurred through the joints between the gutter and parapet wall, the joint between the gutter channel, or the overflow of water from the gutter due to inadequate depth/drainage.
Consequences
Weathertightness has been identified as the most significant defect suffered by curtain walls. Its manifestation can spin off other defects in the long term:
- loss of adhesion of sealant due to chemical reaction of rain water with the constituents of the background materials
- cracking of components due to moisture movement during wetting and drying and during chemical reaction
- increase in condensation and growth of mould
- streaking and staining
- deterioration of joint fittings
These defects may ultimately impair the performance of the curtain wall.