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Beyond Leaks: Why Ponding Water Is Bad for Your Commercial Roof

Posted by Art Valentz on February 8, 2023

Ponding water is the enemy of a flat roof. Water that collects in puddles very occasionally is unlikely to create a problem, but water that collects regularly can create a variety of issues, including leaks, rodents and insect infestation, birds, vegetation, and discoloration. Ultimately, ponding water can do damage to your building and reduce your property's value. 

Commercial property owners who want to take care of their flat roof must watch for ponding water and take precautions against this problem. Knowing why ponding water occurs, how it can be a problem and what commercial property owners can do about it is important. Here's what to know.

What Causes Ponding Water?

Flat roofs are not really completely flat — in fact, they're designed to incline toward a drain into which water runs. Once in the drain, the water runs away from the building. If water is collecting on a flat roof instead of draining, there could be a few different reasons. 

Clogged drain. If the roof drain clogs, then water may collect on the roof around the drain. Rooftop drains need to be cleared occasionally to prevent this from happening.

Dips in the roof. Dips in the roof can form for a variety of reasons. Dips may occur naturally around certain structures like skylights and other rooftop features. Dips can also occur when the insulation in the roof becomes compressed, sometimes due to foot traffic. Having a dedicated roof walkway system can prevent this type of damage. Finally, structural problems and poor design, sometimes caused by improper roof installation, can lead to these dips. 

Leaks from rooftop equipment. Equipment leaks can cause structural damage that leads to depressions in the roof where water can gather. Rooftop equipment that is just too heavy can also cause a depression in the roof over time. Using equipment supports can help distribute the weight of heavy equipment more evenly, lessening the risk for damage.

What Kind of Damage is Caused by Ponding Water?

Ponding water can cause damage in many ways, depending on the environment where the roof is located, how much water collects on the roof, how long it stays on the roof following a rain and other factors. Below is the kind of damage that you can expect to see caused by large puddles forming on your flat roof. 

Leaks. Standing water can cause roofing materials to degrade over time, and that can lead to roof leaks. Flat roofs are designed to repel water, so it does take time before a leak can form, but eventually, it will. 

Rodents, insects and birds. Once a leak forms on a flat roof, the structure beneath can begin to deteriorate. This can lead to infestations of many kinds, as pests start to burrow into the structure and make a home, in much the same way that pests make their homes out of fallen trees in the forest. Wood-eating pests prefer water-damaged wood. Once wood-eating pests move into a structure, it's easier for other larger pests to make their home in the structure as well. 

Vegetation. Algae, moss and other vegetation can grow on structures that stay moist for much of the time. Algae and moss can be difficult to remove, once it's widespread. 

Discoloration. Discoloration can occur on a structure when it stays wet for a long time. This discoloration may never go away - or at least, not until the roof has been repaired or replaced. 

How to Stop Ponding Water from Occurring

There are many things you can do to stop ponding water from occurring on a roof. The first and arguably most important thing you can do is maintain your roof by performing regular inspections and repairs. Your flat roof should be inspected at least twice annually. When inspecting your roof, look for debris like moss, leaves and organic material, and remove it. If you find problems with your roof, such as missing caulking or damaged flashing, hire a licensed contractor to perform the repairs. 

You can also protect your flat roof by making support systems a part of your roof ecosystem. Rooftop support systems give you a place to store your rooftop equipment. Support systems from PHP Systems/Design are designed to disperse the weight of rooftop equipment to prevent it from creating a dip where water can collect.

Support systems also protect the roof from gashes and other damage, and ensure that you can maintain your rooftop equipment so that it will not leak on your roof. This makes it much safer to have equipment on top of your roof, and makes it possible to protect your roof from leaks. 

Need a Rooftop Support System? Call PHP Systems/Design

At PHP Systems/Design, we sell a variety of rooftop support systems to support your rooftop HVAC equipment, electronic equipment, cabling and more. To find out how much PHP products will cost for your roof, call today for a free quote. 

Topics: Roofing Maintenance

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