A leaking commercial window needs a water-path investigation before another bead of sealant. Record where and when the water appears, protect the affected interior and have the window assembly and adjoining wall details reviewed together. The visible drip is an observation; it does not by itself prove which exterior joint failed.
This guide helps property and facility managers prepare a useful service request for offices, retail spaces and other occupied commercial buildings. For broader possibilities beyond the window, see commercial building water-intrusion sources.
Protect the occupied area before investigating
Keep people away from affected electrical equipment and unstable ceiling or wall finishes. Notify the tenant contact and responsible building manager. Have qualified personnel address electrical hazards; do not ask office staff to handle wet fixtures or outlets. OSHA's flood-recovery guidance warns against entering flooded areas or touching electrical equipment when the ground is wet.
Collect photographs only from a safe position. Exterior access, upper-floor work and removal of building components belong in a planned contractor scope. If water is entering now, use the active-leak response guide for coordinating the initial incident; the source still needs to be determined.
Record the pattern, not just the wet spot
Give each affected window an identifier another person can find: building, floor, suite, room and elevation. Record whether water first appears at the head, jamb, sill or surrounding wall. Include a wider photograph showing the whole opening and a closer image of the water or staining.
- When did the leak begin, and did it stop when the rain stopped?
- Does it occur in every storm or only with wind from a particular direction?
- Are neighboring windows or floors affected?
- Has the location leaked previously, and what work was performed?
- Were glazing, wall, roof or sign attachments recently changed nearby?
- What finishes, equipment or business activities are affected?
Keep reported observations separate from guesses. “Water appeared at the east sill during the afternoon storm” is more useful than labeling the cause “bad window caulk” before an inspection.
Review the window and its adjoining details
| Area to review | Useful question |
|---|---|
| Perimeter joints | What is the condition of the joint and its connection to the adjacent wall? |
| Frame and glazing | Which components are installed, and what do their manufacturer details require? |
| Drainage provisions | Are the assembly's intended drainage paths present and unobstructed? |
| Surrounding construction | Could the investigation need to include details above or beside the opening? |
| Earlier repairs | What was changed, and did the leak pattern change afterward? |
Do not seal every visible opening indiscriminately. For example, YKK AP's window accessories manual specifically directs installers not to block weep holes in the applicable sill-flashing detail. That is a product-specific instruction, not proof that every commercial window has the same drainage arrangement. Identify the installed system before choosing a repair.
If controlled water testing or selective openings are proposed, agree on the test area, occupant protection, approvals and restoration responsibility first. The report should distinguish a suspected path from one supported by testing.
Approve the exterior correction and interior follow-up together
A useful proposal identifies the opening, the defect being addressed, material compatibility, preparation, access and any testing or follow-up. Confirm whether work is temporary protection or a permanent repair. Review applicable warranty requirements before authorizing changes to a proprietary assembly.
Assign responsibility for affected finishes as well as the entry point. Avoid closing the work order simply because the sill is dry on a sunny day. Request a completion record and an agreed method for checking whether the original complaint returns.
Common questions
Will resealing the window stop the leak?
It may if the investigation confirms an appropriate sealant-joint repair. It will not answer every frame, drainage or surrounding-wall problem. Ask how the proposed repair connects to the observed leak.
Should building staff run a hose over the window?
Arrange any diagnostic testing through the assigned specialist. Informal testing can introduce water without producing a reliable record of its entry path.
Can the issue be investigated between storms?
Yes. Records and accessible conditions can be reviewed in dry weather. The investigator should explain whether further testing or observation during rain is needed.
Discuss a commercial water-intrusion assessment
Brady can discuss commercial water-intrusion investigation and repair coordination, including properties served through our Ontario and Temecula inspection service areas. Request service with the address, affected openings and photographs, or call 909-293-9861.