Roof ponding is the occurrence of accumulating water that stagnates on a roof's surface for more than 48 hours. These large pools of water can manifest on a roof's surface for many reasons. While some amount of water can be normal, the significant amount of water that eventually becomes roof ponding poses a risk to the structural integrity of the building.
Because of the high volume of water present on the roof, evaporation fails as there's nowhere for it to drain. With the help of Northpoint Roofing Systems, you'll learn what causes roof ponding, how to fix it, and how to prevent it in the future.
What Causes Ponding Water on a Flat Roof
Now that we've covered what roof ponding is, how does it start? Roof ponding can stem from a variety of causes; let's look deeper at each one.
Roof Design
One of the most common causes of ponding water on a flat roof is poor roof design. This usually happens when the plans for a roofing project don't align with the roof's shape or building layout, creating the opportunity for issues to follow. If roofing components like the joists and beams aren't taken into account to prevent pooling water, the roof is put at risk of water accumulation.
Age
Even if the roof is well-designed and was made with the best materials, the amount of time the foundation has settled plays a role. There is a greater likelihood of ponding water as the roof gets older and the building settles.
Rubber Roofs
Rubber roofs are made up of multiple layers. When rubber is laid over the underneath layers of tar and gravel, it's not a guarantee it's perfectly leveled the way it should be. Due to improper leveling, the roof's slopes can become a bigger issue and create the opportunity for roof ponding.
Crushed Insulation
The insulation-based layers of a roof are often of malleable materials. The insulation layer is susceptible to becoming uneven and crushed due to large amounts of snow and heavy foot traffic. The result of uneven surfaces due to crushed insulation is the perfect opportunity for roof ponding.
Lack of Drainage
Sufficient drainage is crucial for a roof. A roof can fail to stay dry and drain excess water when the design is poor. Without proper drainage, roof ponding and ensuing damages become more likely.
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How To Fix Ponding on a Flat Roof
If you've experienced recent roof ponding, what can you do to fix it? There are two avenues you can take: the repair/replacement route or the spray foam option. Roof repair or replacement would be the best path forward if the ponding water has caused small amounts of damage or if damage has left the roof and the structural integrity of the building compromised. Roof repair or replacement from the right team of professionals like the experts at Northpoint Roofing Systems would be the better choice long-term.
If roof ponding hasn't caused damage, the usage of specialized roofing spray foam is a viable short-term option. This method costs less and involves fewer moving parts. The specialized spray foam can be applied to the affected area, restoring the functionality of the roof in a quick turnaround.
How To Prevent Roof Ponding
In the future, how can you prevent roof ponding? Let's discuss the avenues you can take to prevent ponding water from the roof of your building.
Clean and Flush Roof Drains
Roof ponding is commonly the result of clogged drains. Clean and flush the drains related to your roof, if this is the culprit the ponding water will cease to persist.
Install Additional Drain
Another method would be to install an additional drain. Installing a new scupper and downspout is especially a helpful tool if ponding water is happening near a parapet wall and can help keep water from pooling.
Silicone Based Repair
Silicone roof coating is one of the few solutions known to withstand pooling water. Silicone-based repair can be applied to the area where water is collecting to further protect your roof and building from ponding water and future damage. This method should be done by a professional.
Roof Crickets
Preventing roof ponding can also be done by replacing the membrane from the affected area and installing roof crickets. The installation of roof crickets allows for future accumulation of water to be diverted away from the area, eliminating the possibility of ponding water for that section of the roof.
SPF
As mentioned before, specialized roofing spray foam can be applied to the lowest section of a roof where water ponding has been an issue. For complete effectiveness, the SPF material must be coated with UV-resistant material.
Repitch Roof
The installation of a new tapered foam-board system to repitch the roof is also an available option to prevent roof ponding. In situations where a flat roof has multiple areas of pooling water, repitching the roof with a taper system could be required.
Overlay with New Membrane
An overlay with a new membrane is an excellent option when water is ponding and the roofing materials are starting to age out. Roof crickets would be installed on top of the existing roof where ponding is present and the new membrane is then installed over the entire roof.
Replace Roof
The most significant option for roof ponding would be a full replacement of the roof. This way, your new roof replacement can be better designed to prevent roof ponding from becoming an issue.
Flat Roof Repair
Ponding water on a flat roof is serious and must be addressed as soon as it's noticed. Since the stagnant water can't evaporate, roof leaks and complications to the building's structure are at risk. If the need for flat roof repair becomes a need for your building, turn to Northpoint Roofing Systems. Our team is ready to deliver the professional repair solutions your flat roof needs to effectively protect your building again.