Written by Ben Adams (ben@wpgusa.org)
If you manage a commercial property in Metro Atlanta, you’ve probably noticed standing water on a flat or low-slope roof after a heavy storm. In most cases, that’s normal — flat roofs are designed to shed water gradually, not instantly. But when that water sticks around, it stops being a minor drainage quirk and starts being a warning sign.
At The Waterproof Group, we get calls every storm season from property owners and facility managers asking the same question: is this ponding water actually a problem, or will it dry out on its own? Here’s how to tell the difference, and what to do if it turns out to be the former.
When ponding water is normal — and when it isn’t
Some standing water after rainfall is expected, especially during Georgia’s frequent summer storms. It becomes a concern when:
- Water is still sitting in the same spot 48 hours after the rain has stopped
- The same area ponds after every storm, not just the big ones
- The ponding area is spreading or getting deeper over time
- Water is collecting near seams, flashing, drains, or rooftop equipment
- You notice membrane wear, cracking, blistering, or signs of a roof leak
- Drains, gutters, or scuppers look clogged with debris
- Algae, moss, or sediment has started forming where the water sits
That 48-hour mark is the industry rule of thumb for a reason: most roofing membranes can handle brief exposure to standing water without issue, but prolonged ponding accelerates wear, stresses seams, and creates the exact conditions mold, leaks, and structural damage need to take hold.
Why this matters more here in Metro Atlanta
Georgia’s climate makes commercial roof ponding water a bigger concern than it might be elsewhere. Heavy, frequent rainfall combined with high humidity slows natural dry-out time, so water that would evaporate quickly in a drier climate can linger for days. That extra time sitting on the roof can turn a minor drainage issue into a membrane or structural problem — and it’s why we tell every property owner we work with to keep an eye on ponding water after every storm, not just the ones that make the news.
What’s usually causing it
Ponding water is rarely random. In our experience, it almost always traces back to one of a few root causes:
- Poor or inadequate roof slope — flat roofs need at least a slight pitch to drain properly, and that pitch can settle or shift over time
- Clogged or undersized drains — leaves, debris, and sediment build up faster than most maintenance schedules account for
- Structural sag — years of load, foundation settling, or water weight itself can create a low spot that never fully drains
- Damaged or aging membrane — once a membrane starts to sag or deteriorate, it can create new low points where water collects
What to do about it
If you’re seeing any of the warning signs above, the next step is a professional roof and drainage assessment — not guesswork. When our team evaluates a commercial roof for ponding water, we look at the whole system: membrane condition, drain and scupper performance, seams, flashing, penetrations, and the areas where water is actually collecting. You get a clear, documented picture of what’s happening and what it will take to fix it, whether that’s a targeted repair, improved drainage, or a broader roof restoration.
That’s the same approach we bring to everything we do — an honest inspection and a straightforward recommendation, not an upsell. Ongoing roof maintenance can also catch a drainage problem like this before it becomes a full assessment in the first place.
Schedule a Free Roof Inspection
If ponding water has been showing up on your commercial property after every storm, don’t wait for it to become a leak. The Waterproof Group has been serving property owners and businesses throughout Metro Atlanta since 2015, and we offer free, no-obligation inspections for commercial roofing, drainage, and waterproofing concerns. Click the button below to schedule your free evaluation today, or give us a call (678) 223-4948
