How long should a waterproofing ponding test last?
BCA's Quality Mark scheme, used to assess new homes, ponds bathrooms and roofs above living areas for at least 24 hours on the finished floor, with bathrooms flooded to at least 25 mm measured from the highest point. It is a sensible benchmark to write into a repair specification. For roofs, check the structure can carry the water load, seal outlets temporarily and keep an overflow route, because a blocked roof under heavy rain is a real risk.
From the RRD Field Guide, checked against the sources cited in Flat Roof and Wet-Area Waterproofing in Singapore: Membranes, Ponding, Leak Tracing and Repair. General information, not advice for your project.
The fuller picture
Most flat-roof and bathroom leaks in Singapore come from failed membrane details, not the open field: upturns, outlets, penetrations and laps. Diagnose before repairing, using a controlled flood (ponding) test, moisture mapping and inspection. The code of practice is SS 637:2018. In strata buildings the roof membrane is common property, so the MCST repairs it.
More questions on this topic
- Which is better: torch-on, liquid or cementitious waterproofing?
- Who pays for a roof leak into a top-floor condo unit?
- Can I just coat over my old roof membrane?
- What does a waterproofing warranty usually cover?
- Why does my roof leak only during some storms?
- Do I need BCA approval to redo roof waterproofing?