Case 3
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Introduction
Ponding
Type of Building: Commercial
In this case, it is observe that there is accumulation of water, the rainwater retained at the lowest end of the roof gradient and is not drain off.
Ponding is the retention of water caused by the lack of an adequate gradient to fall or unevenness, such as a deflection of the roof’s underlying structural components. Ponding water on a roof may cause the
waterproofing system to deteriorate, resulting in water leakage as well as algae and fungal growth. The generally accepted minimum fall is 1 in 80 although some codes recommend 1 in 40 to leave an allowance for any inaccuracies on the site and any possible deflection of the roof structure. Ponding occurs when there is unevenness in the slab surfaces. Regular inspection should be conducted regularly to detect the occurrence of new ponding problems. When ponding happens, immediate repair is needed. Apply a layer of screed so as to level the surface and take note of the fall, directing the flow of the water to the drainage area.
