Roof Ponding Nearly Became a Disaster of Total Roof Collapse
When we arrived at a home in Sonoma County for an emergency roof leak repair, we found something that should never exist—a rooftop pool. Over 13,500 pounds of water had collected on the flat roof, turning it into a ticking time bomb. This wasn’t just a minor drainage issue. The roof was designed to hold only 10 pounds per square foot, but under the weight of the water, it was carrying nearly double that.
Had this been ignored for much longer, the outcome could have been catastrophic. Water had already begun leaking into the home, damaging multiple rooms, including the main bedroom. The weight of the trapped water was enough to cause structural deflection, a clear warning sign that failure was imminent.
Our team at Wedge Roofing acted fast to prevent a disaster.
How Wedge Roofing Solved the Problem
The first priority was to get the water off the roof before the structural load increased further. We cleared the primary drain immediately, which allowed the majority of the water to drain rapidly. The second drain remained blocked and required a plumber to clear it the following day, ensuring complete drainage and preventing further buildup.
After handling the immediate danger, we turned our attention to the structure itself. A full inspection revealed that, despite the extreme weight, the roof had not yet suffered permanent structural failure. However, it had reached a dangerous threshold, and any further stress could have led to severe damage or collapse.
One of the most concerning findings was that the home lacked emergency overflow drains, a safeguard required in modern roofing systems. These secondary drains are designed to prevent catastrophic ponding by providing an additional outlet when primary drains become blocked. Without them, this home had no failsafe, and the situation could have quickly spiraled into disaster.
Watch as We Drain this Dangerous “Rooftop Pool”
Standing water on a flat roof is more than just an inconvenience—it’s a structural threat. In the video below, the real dangers of ponding water as we drain the “rooftop pool.” You’ll see just how much water had collected and why immediate action was critical to preventing a collapse.
This Could Have Been Another News Headline
Recently, in Southern California, a grocery store roof collapsed during a storm, crushing the building under the weight of standing water. That failure was the direct result of what we saw firsthand in Sonoma—a roof forced to hold far more than it was designed for, with nowhere for the water to go.
Watch the News Video of the Grocery Store Collapse:
The difference was that the homeowner we helped took action in time.
What Homeowners and Businesses Must Do to Avoid Disaster
1. Schedule regular roof inspections. Even if your flat roof seems fine, minor issues can turn into significant problems overnight. You can easily sign-up for our annual roofing maintenance/inspection plan here: https://www.wedgeroofing.com/roof-services/roof-maintenance
2. Ensure your roof has proper drainage. Ensure primary drains are clear and emergency overflow drains are installed per modern building codes.
3. Be proactive, not reactive. The cost of maintaining a roof is far less than the cost of a collapse.
Why Every Flat Roof Owner Needs to Take Ponding Water Seriously
If a flat roof is draining properly, water should not sit for long periods. But as we saw in Sonoma, problems often go unnoticed until it’s almost too late.
Many cases of ponding water begin with clogged drains, the most common and easily preventable cause. Older roofs often lack emergency overflow drains, which provide a crucial backup system when primary drains fail. Even minor sagging in the roof structure can create low points where water collects, adding stress and increasing the risk of further deflection. Left unchecked, these factors can turn a manageable issue into a significant structural risk.
Don’t Wait Until the Damage is Done
The homeowner we helped in Sonoma made the right call before it was too late. Had they ignored the signs, they might have faced a catastrophic collapse like the one in Southern California.
At Wedge Roofing, we’ve seen firsthand what happens when ponding water is left unaddressed. That’s why we emphasize preventative inspections, proper drainage systems, and emergency response when it matters most.
Watch our video to see precisely what we found on the rooftop pool and why taking action made all the difference.
Contact Wedge Roofing today for a flat roof inspection before the next storm tests your roof’s limits.
#WedgeRoofing #FlatRoofSafety #PondingWater #RoofDrainage #SonomaRoofing #MarinRoofing #RoofCollapse #RoofPooling #PoolingRoof #PondingRoof #StandingWaterOnRoof
