Case 1
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Cause of Defects
Materials tend to sag under under loading. Structural Members are designed to carry its own weight, live and dead loads. If the design of the structural members are insufficient, the members will deflect. The roof deck must account for the dead loads imposed by roofing systems and live loads imposed by the rain. Rainwater does not accumulate evenly over flat roofs and accumulates at local depressions. Roofs slabs with excessive deflection forms local depressions and thus results in the accumulation of water.
The picture and illustration below shows that the roof is sloping toward the back side of the building, which allowed rain water to accumulate there. Being a rather long kerb, water has no diversion to get around the kerb, so water will accumulate along the base of the kerb flashing.