Water Ponding

Ponding will create a prolonged time of wetness and increased build-up of debris. Ponding will detract from a coated steel product’s life and will invalidate the product warranty.

The installation of penetrations must be done in such a way that they do not cause ponding. See External Moisture: Penetrations.

On low pitched roofs, careless or excessive foot traffic may cause rib damage and localised ponding. This can be minimised by installing temporary protection in critical areas, such as entry points, where the roof is accessed by other trades, or there is a step-down in the roof. It is the main contractor’s responsibility to ensure that other trades do not damage the roof.

It is recommended to design to Unrestricted Access-criteria or better if roofs are highly visible or need to be regularly accessed by maintenance personnel.