Blog · Ohio & Michigan
Flat roof leaking? What facility managers should do in the first 48 hours
A practical plan for commercial and HOA flat roof leaks in Ohio and Michigan: protect the building, find the source, document it, and decide repair, coat or replace.
By Jonathan Blake · · 2 min read
- Protect people, equipment and inventory first. Then find the source.
- On a flat roof, water can travel far before it shows up inside. The drip is rarely under the hole.
- A leak log plus a moisture survey decides whether you repair, coat, recover or replace.
A leak in a warehouse, school, office or condo building isn’t just a roof problem. It can shut down equipment, ruin inventory and create slip hazards. Here’s a 48-hour plan.
Hours 0 to 4: protect the building
- Move people, equipment, inventory and records away from the water.
- Put down buckets and tarps, and mark wet floors.
- If water is near electrical equipment or light fixtures, shut off power to that area and call an electrician.
- If the roof is under warranty, check who you are supposed to call first.
Hours 4 to 24: find and document
Water on a low-slope roof travels. It can run along the deck or between insulation boards and show up far from the opening. Record:
- Where water appears inside, marked on a floor plan.
- When it started and what the weather was: heavy rain, wind-driven rain, snowmelt or a thaw.
- Photos inside and, only if it is safe and permitted, from the roof access point.
- Any recent rooftop work: HVAC service, new equipment, satellite dishes or solar.
Our inspection intake organizes this into a summary you can hand to a roofer.
Hours 24 to 48: get it inspected
Have a commercial roofer who works on your membrane type (TPO, EPDM, PVC, modified bitumen or metal) find the source and make a temporary repair. Ask for photos of what they found and what they did.
Then decide: repair, coat, recover or replace
| Condition | Usual next step |
|---|---|
| One source, dry insulation, membrane in good shape | Repair |
| Aging but dry membrane, small wet areas removed | Coating may qualify |
| One existing roof layer, limited wet insulation | Recover may qualify |
| Large wet areas, failed membrane, deck damage | Replacement |
A moisture survey tells you which row you’re in. Screen the options with the coating feasibility check and the replace or recover planner, then compare budget ranges in the commercial roof cost planner.
Prevent the next one
Most flat roof leaks start at seams, flashings, drains and rooftop equipment. Two inspections a year, spring and fall, plus a check after big storms, catch most problems while they’re small.
Free download: post the flat roof leak response checklist (PDF) in your maintenance office.
Run your numbers
Quick commercial roof estimate
Provisional planning range (our setting, not a quote or market average). Real prices depend on condition, access and scope.
Questions readers ask
Why does my flat roof leak far from where the water comes in?
Water can run along the deck, insulation joints or structural members before it finds a way down. The leak inside may be many feet from the opening in the membrane.
Can a flat roof be repaired in winter?
Temporary repairs usually can. Many permanent membrane repairs and coatings need dry surfaces and minimum temperatures, so the full fix may wait for suitable weather.
How do I know if the whole roof needs replacing?
A moisture survey shows how much insulation is wet. If only small areas are wet, repairs or a coating may work. If large areas are wet, replacement is usually the better investment.
Who should I call for a flat roof leak?
A commercial roofing contractor that works on your membrane type. If the roof is under warranty, call the installer or manufacturer first so the warranty isn’t affected.
Sources
- Selecting a professional roofing contractor, National Roofing Contractors Association (NRCA)