How Do You Stop Water From Ponding On A Flat Roof?
Ponding water can do a substantial amount of damage to a flat roof, so it's important to prevent it. Water standing on the roof can leach away oils in the asphalt in a built-up roof, causing the asphalt to weaken and turn brittle. It will also wear away the membranes on a single-ply membrane roof, causing them to fail more rapidly and allowing the roof to leak. In the worst-case scenario, a large amount of ponding water on your roof can cause the roof of your building to collapse under the immense weight.
Preventing water from ponding on your roof will extend its lifespan and prevent structural damage to your building. To learn how you can stop water from ponding on a flat roof, read on.
Keep Your Exterior Drainage System Clean
The most important thing you can do to prevent ponding water on your roof is to make sure the drainage system is kept free from clogs. A flat roof has a gentle slope that causes water to flow toward the scuppers and downspouts at the edge of the roof. Any water flowing out of the scuppers simply lands on the ground from the roof's edge, while the water flowing into the downspouts is carried down to the ground through a drainage pipe.
Scuppers and downspouts can both become clogged with debris, preventing water from draining off of your roof. Since the slope of a flat roof is very shallow, a clogged downspout or scupper will cause water to pool at the entrance to the drain. It won't flow anywhere else on the roof because of the gentle slope of the roof. You can hire a commercial roofing service to periodically clean your exterior drainage system in order to make sure that all of the rain that lands on your roof is carried to the ground rather than collecting on your roof.
Use Roofing Cement to Fill in Valleys in Your Roof
Since a flat roof has a very gentle slope, even a shallow valley in the roof will collect water. A valley in a flat roof is often caused when the insulation layer of the roof is compressed by contractors or maintenance workers walking on the roof.
Whenever a valley appears in your roof and collects water, you'll need to have it filled in by a commercial roofing service. They will use roofing cement to raise the valley, which will prevent rain from collecting in it. Once the valley is filled, the rain will flow toward your exterior drainage system as intended.
Install Interior Drains to Allow Water to Drain in Freezing Weather
If you live in an area where temperatures drop below freezing in the winter, you'll usually need interior roof drains on your flat roof. Water can freeze in your exterior drainage system, clogging it and preventing your roof from shedding water. An interior roof drain is connected to a pipe that runs through the inside of your building. As long as your building is heated during the winter, there's no risk of rain or melted snow in the pipe freezing. This allows your roof to keep shedding water properly even when your exterior drains are frozen.
If you have water ponding on your flat roof, call a commercial roofing service and have it inspected. They'll fill valleys with roofing cement to improve drainage, and they'll also make sure your exterior drains are free from clogs. If you need interior drains to deal with freezing weather, they'll also be able to design and install them for your building. Ponding water will shorten the lifespan of your roof, so preventing it can save you money by extending the time until it will need to be replaced.
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