Case 1
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Good Practices
The membrane should be applied to cover the whole roof and have an upturn of at least 300mm and tucked into parapet wall. In addtion, a counter flashing can be used to prevent any ingress of water through the edges of the membrane upturn.
There should be a water-tightness test carried out after the membrane has cured for at least 24 hours. The minimum flooding period should be 24 hours. No dampness should be observed within an hour after the test duration.
If performed membrane is used, all areas laid should be checked for air trapped between it and the concrete surface or between successive layers of the membrane. This is to ensure there is no gaps in between the two layers which would allow water to accumulate.
End laps of the preformed membrane should be at least 75mm and the side laps should be 50mm unless otherwise stated by the manufacturer. End laps between each roll should be staggered.