A Flat Roof Leak Guide: From Symptom to Repair Plan

What to check first

• Record when and where the leak appears.
• Inspect nearby and uphill transitions, outlets, and penetrations.
• Stop repeated patching if the substrate is wet, soft, or deteriorated.

Build a repair plan from evidence

1. Record the pattern

   Note the indoor location, timing, rain direction, and whether water appears after the rain has stopped. Photos and a simple sketch help compare the symptom with the roof above.

2. Inspect the likely entry points

   Check visible seams, flashing terminations, penetrations, drains, and wall details. Water can travel within an assembly, so the area directly above a stain is only a starting point.

3. Match the scope to the damage

   A sound, dry surface with one confirmed defect may suit a localized repair. Wet insulation, soft decking, or repeated failures need investigation before another surface patch.

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