Start with drainage and safety
Document the time since rainfall, approximate extent from a safe position, interior leaks, affected operations, and whether rooftop equipment or recent work changed drainage.
Possible causes
- Blocked or undersized drains and scuppers
- Insufficient or interrupted slope
- Settled or compressed insulation
- Structural deflection or deck problems
- Improperly placed curbs, sleepers, or equipment
- Membrane wrinkles, ridges, or repairs that redirect water
- Overflow paths that are blocked or absent
What the inspection may require
The roofer may review membrane condition, seams, flashings, penetrations, drains, edge details, prior repairs, and available drawings. Moisture scanning, test cuts, core samples, or structural evaluation may be appropriate when conditions cannot be established visually.
Coating over ponding water or wet insulation is not a universal solution. Compatibility, preparation, drainage, attachment, moisture, and warranty requirements must be established first.
Build a documented maintenance record
Track inspection dates, drainage cleaning, leak locations, weather, photographs, rooftop contractors, repairs, warranties, and tenant or operations impacts. A consistent record makes recurring leaks easier to diagnose and capital work easier to plan.
Building operations belong in the repair plan
Leaks may affect tenants, inventory, electrical equipment, production, healthcare, food service, or customer access. Tell the roofing company which areas are sensitive and who controls rooftop equipment and interior access.
A complete scope may need phased work, temporary water control, odor or noise planning, protected entrances, shutdown coordination, and communication with property management.
Capital-planning questions
- Is the surrounding insulation dry and serviceable?
- Are recurring repairs concentrated or widespread?
- Can drainage be corrected within a repair scope?
- Is the membrane compatible with proposed restoration?
- What roof layers and warranties already exist?
- Will new equipment or energy work alter the assembly?
- When does replacement become more economical than repeated repair?
What is causing it
| Cause | How it shows |
|---|---|
| Blocked or restricted drains and scuppers | Clears slowly once cleared; debris at the outlet |
| Deck deflection between structural members | Ponding in regular bays, often mid-span |
| Settlement or structural movement | Concentrated in one area, sometimes worsening |
| Insufficient or damaged tapered insulation | Broad, shallow ponding across a wide area |
| Original design with inadequate slope | Present since construction, in consistent locations |
| Added rooftop equipment obstructing flow | Water backing up on the upslope side of a curb |
How it changes the options
The decisive question for any significant work is whether the insulation beneath is wet, because that determines what remains available. A moisture survey answers it; a coating applied over wet insulation conceals the problem while adding cost and complicating eventual replacement.
Correcting drainage is a real decision point at replacement. A new membrane laid over an assembly that never drained will pond exactly as the old one did. Tapered insulation, additional drains, or crickets between drains are how the geometry actually changes, and they belong in the conversation explicitly rather than being inherited by default.
Primary sources
Published August 12, 2026 and last reviewed August 16, 2026 by Greater Burlington Roofing. General roofing information; an on-site inspection is required for property-specific recommendations.