Standing Water After a Storm: What Commercial Property Managers Should Do

The rain has stopped, but a pool of water is still visible on the roof. Is it something to record for the next maintenance visit, or does the building need attention now?

For property managers, the most useful response is a short, consistent process. Record what happened, check for signs of water entry, and determine which roofing service fits the situation. You do not need to diagnose the roof from a photograph, but good observations can help a roofing professional investigate it faster.

First, check the building interior

Look for new ceiling stains, dripping water, damp wall finishes, affected inventory, or moisture around electrical equipment. Ask tenants or facility staff when the signs first appeared and whether they have happened during previous storms. An interior leak may be some distance from the roof opening because water can travel within the assembly before becoming visible.

If water is actively entering the building, protect people and property, follow your facility’s response procedures, and request a commercial roof repair evaluation. Do not wait 48 hours to see whether the rooftop pool disappears. If water is close to electrical equipment or another immediate hazard, involve the appropriate building personnel right away.

Record the drainage pattern without guessing at the cause

From a safe, authorized vantage point, photograph the standing water and the surrounding roof area. Include a wider view showing the nearest drain, scupper, parapet, or rooftop equipment; a close view alone can make it difficult to locate the problem later. Note the date, approximately when rain ended, whether the storm was unusually heavy, and whether the same area has pooled before.

Take another photograph when conditions permit the next day. If water remains after roughly 48 hours in weather conducive to drying, flag it for evaluation. The National Roofing Contractors Association’s definition of ponding refers to excessive water remaining more than 48 hours after precipitation under favorable drying conditions. Cold, shaded, or continuously wet conditions can make a simple clock-based judgment less useful. A recurring or growing pool deserves attention even when it dries sooner.

Do not send untrained staff onto a wet roof to measure depth, move debris, or test for soft areas. A safe observation and a clear record are more useful than an unsafe attempt to diagnose a concealed condition.

Check what changed since the last storm

Compare current photos with earlier inspection reports or roof images. Has the pool expanded? Is it forming in a new place? Did the building recently have HVAC service, electrical work, plumbing work, or equipment replacement? Materials left near a drain or a change around an equipment curb may affect how water moves, but a photo cannot establish the full cause.

Review the roof access log, repair records, and warranty paperwork as well. Peterson’s article on commercial roof warranty documentation explains which records are useful to keep together. Document who accessed the roof and what work was performed, especially when another trade was there shortly before the drainage changed.

This record also helps separate a one-time storm observation from a pattern that has developed over months. If several buildings are involved, use the same photo locations and notes at each property so you can compare conditions consistently.

Decide which kind of follow-up fits

There is no single response for every puddle. Use the condition of the building and the pattern you documented to choose the next step:

• Active water entry or visible membrane damage: Request a repair evaluation promptly. A leak, open seam, damaged flashing, or puncture needs attention beyond routine monitoring.
• A blocked or debris-covered drainage area without an active leak: Arrange appropriate commercial roof maintenance under an approved scope. If water keeps collecting after the outlet is serviced, investigate further.
• Recurring ponding, an expanding low spot, or uncertain roof condition: Schedule Peterson’s paid Professional Commercial Roof Inspection to document accessible conditions and identify whether more investigation is needed.
• A large, deep, or rapidly worsening pool: Contact a qualified roofing professional promptly. Significant added water weight or suspected roof movement may require a structural assessment; do not assume the membrane alone explains the problem.

A visual inspection can describe what is observable, but it cannot confirm that insulation or decking beneath the membrane is dry. If the findings raise a moisture or structural question, the next step may involve a separately scoped investigation.

Do not cover a drainage problem with a quick surface fix

It is tempting to request a patch or coating where water sits. That may be appropriate for a confirmed membrane defect, but it does not necessarily restore the path to a drain. Depending on the roof, the issue could involve an obstructed outlet, a low area, compressed insulation, altered slope, or equipment blocking runoff. GAF’s discussion of low-slope drainage shows why these conditions need to be considered together.

An evaluation should connect the proposed work to the observed cause. That might mean clearing a drain, repairing a damaged detail, investigating wet materials, or planning a drainage correction. It does not automatically mean replacing the roof.

Make the next storm easier to assess

Keep a dated set of roof photos, inspection findings, maintenance records, and notes about rooftop work in the property file. Identify the areas that have pooled before and review them after major rain or snowmelt. When you contact Peterson Roofing, share the photos, timing, leak history, roof age if known, and the outcome you need: immediate leak response, maintenance, or a documented inspection.

Peterson Roofing serves commercial properties in Mount Prospect, the Northwest Chicago suburbs, and surrounding Chicagoland communities. If standing water is recurring or the building shows signs of leakage, call (847) 590-5290 to discuss the appropriate evaluation.