Water near a rooftop HVAC unit can come from the roof, the equipment or the connection between them. Flashings, service penetrations, equipment interfaces, condensate drainage and nearby roof drainage may all need review. The ceiling location does not assign responsibility. Record when the leak occurs and request an investigation that connects roofing and mechanical findings.
For a commercial property manager, the practical goal is to avoid two separate visits that each end with “call the other trade.” Give the roofing and HVAC teams the same incident information and establish who will coordinate the next step. An active leak also requires appropriate protection of the occupied area; use our during-storm response guide first if water is entering now.
There is more than one connection around a rooftop unit
A rooftop unit may sit on a raised curb at an opening in the roof. The roof flashing around that curb, the equipment-to-curb connection, nearby piping and wiring penetrations, and the unit's own moisture-management components have different functions. A defect at one interface is not necessarily corrected by work at another.
Johns Manville's roof-maintenance guidance addresses equipment flashings, penetrations, condensate drainage and protection around equipment service areas. These are useful inspection categories. The actual repair detail must fit the installed system and its applicable requirements.
Also distinguish rain entry from mechanical moisture. The EPA's commercial-building moisture guidance includes HVAC condensate and condensation alongside roof and enclosure moisture control. A complaint described as a roof leak may therefore require mechanical investigation even when the water appears beneath rooftop equipment.
What does the timing tell you?
Timing helps define questions; it does not prove which component has failed. Record what happened without changing equipment settings or entering restricted areas to test a theory.
| Observed pattern | Useful follow-up question |
|---|---|
| Water appears during rain | Which roof, curb, equipment-enclosure and adjoining details were checked for rain entry? |
| Water also appears in dry weather | Should condensate drainage, condensation or another building-system source be investigated? |
| The complaint started after equipment work | What work occurred, and which roof or equipment connections were disturbed or added? |
| Only certain storms produce a leak | Was the pattern associated with rainfall duration, wind direction or surrounding drainage conditions? |
| Several ceiling locations are affected | Are they connected to one incident, or are there separate sources requiring their own investigation? |
Do not ask staff to open energized cabinets, disconnect drains, lift equipment or climb onto a wet roof. For intermittent storm patterns, our heavy- and wind-driven-rain leak guide explains the records that are most useful.
Give each trade a defined question
The roofing review should address the roof system and the relevant flashings, penetrations, earlier repairs and surrounding drainage. The mechanical review should address the equipment and its relevant drainage, enclosure and operating conditions. Where those scopes meet, identify who is responsible for evaluating the connection.
Ask the coordinator to combine the findings rather than close the complaint as two unrelated work orders. If neither scope confirms the cause, record the next investigation step and the authorization needed. Avoid assigning fault before the condition is established.
- Give both providers the same leak-location references and incident dates.
- Share recent HVAC and roof-service records, including what was changed.
- Make existing roof and equipment warranties available before repair work is selected.
- Clarify access, tenant notification and any proposed interruption of equipment operation.
- Agree who communicates the findings and obtains approval for additional work.
Our commercial roof leak detection guide explains how inspection and suitable testing can support a more specific repair decision.
Prepare a service request that supports the first visit
Send the property address, suite or bay reference, on-site contact and a brief description of the operational impact. Add the equipment identifier if it is available in your normal records. Include safe interior photographs, the first-observed time, whether it was raining, and whether similar water has appeared during dry weather.
Attach the most recent related service ticket rather than summarizing it from memory. A ticket showing a new penetration or equipment connection gives the investigator a specific item to review; it does not prove that the recent work caused the leak.
Request a repair scope that separates the confirmed cause, proposed corrective work and any remaining uncertainty. Clarify whether temporary protection is included, who handles affected interiors and what follow-up will close the complaint. Blanket sealant application, a new ceiling tile or a roof coating should not substitute for identifying the relevant defect.
Brady can discuss coordination between commercial roof leak repairs and building systems maintenance. The assigned personnel and qualified specialist partners depend on the approved scope. For properties in Ontario and other Southern California communities, confirm the site requirements when requesting service.
Common questions
Should I call an HVAC contractor or a roofer first?
Report the observed conditions and arrange coordination between the relevant scopes. Rain timing, dry-weather occurrence and recent work help frame the request, but the leak location alone does not establish which trade must repair it.
Can condensate look like a roof leak?
Yes. Mechanical moisture problems can appear in ceiling areas beneath rooftop equipment. Dry-weather occurrence is useful information to give the investigator; it is not a diagnosis by itself.
Will sealing around the unit solve it?
Only if the proposed work addresses the confirmed defect with a compatible detail. Indiscriminate sealing can leave the actual cause unresolved. Ask which connection is being repaired and why.
Can roof and interior repairs be coordinated together?
They can be reviewed as one coordinated scope. Source correction, affected material condition and any electrical, drying or specialist work should be addressed before finish restoration is completed.
Request a coordinated rooftop leak assessment
Send the property details and available equipment or leak records, or call 909-293-9861. Confirm access, scheduling and the proposed scope directly. For broader symptoms, review seven sources of commercial building water intrusion.