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Roof Drainage Maintenance Guide: How to Ensure Proper Water Flow

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Proper roof drainage is essential for maintaining the integrity of your building. Keep reading to learn about the importance of a well-functioning roof drainage system and practical tips on how to keep your drains clear and water flowing smoothly. From understanding how flat roofs drain to tackling standing water in gutters, we cover everything you need to know to maintain effective roof water drainage.

Understanding Roof Drainage Systems

Water damage can diminish the value of your building and result in increased maintenance costs, lower productivity and a decline in indoor air quality. The first step to protecting your building from water damage is understanding the roof draining system.

  • Gutters and downspouts direct water on roofs away from buildings, protecting both the building exterior and the foundation and keeping water from running off the roof straight down the side of the building to the foundation.
  • Internal drains run water from the roof into pipes that go through the building; these usually discharge into a storm sewer system.
  • Scuppers are openings at a building’s perimeter that allow water to drain into a downspout; usually located by a metal box that acts as flashing and directs water to run through the wall.

Common Roof Drainage Issues and Their Consequences

The roof gets more abuse from the elements than any other part of a building. Check out this list of general guidelines to keep your roof in good working condition. Be sure to avoid these three common roof draining issues and their consequences:

  • Clogging hazards—Debris, leaves, branches and ice can quickly clog drains, especially during a heavy storm.
  •  Standing water on flat and slanted roofs—One inch of standing water adds five pounds per square foot of roof, or about 2,000 pounds of weight on a 20' x 20' square foot roof. And if drains or gutters are clogged, even a slanted roof can have standing water, resulting in foundation or basement problems.
  • Potential damage to roofing materials and building foundations—Standing water can also deteriorate roofing materials, such as membranes and shingles, and can work its way under flashing and other sealants. Additionally, a freeze-thaw cycle can cause cracks in many roofing materials, allowing water to seep through to the interior.

Maintaining Optimal Roof Drainage

Being observant and proactive when it comes to roof maintenance is important to keep drains flowing. The Insurance Institute for Business and Home Safety recommends these maintenance tips:

  • Inspect and clean roof drainage systems regularly, ideally every spring and fall, and after severe weather.
  • Remove obstacles and debris from roofs and gutters and keep tree branches away from the roof so leaves don’t clog roof drains.
  • Thoroughly clean and inspect gutters and downspouts, including running water through them to ensure they aren’t clogged. Be sure to check for sagging, loose connections and broken or missing fasteners as well.
  • Repair any cracks and ensure that strainers are secure
  • Promptly address standing water issues
  • Redirect water away from the building
  • Consider upgrading roof drainage components during re-roofing or gutter replacement

By following proper maintenance practices, you can ensure that your roof drainage system functions optimally, preventing potential damage to your building. Regular inspection, cleaning and timely repairs will help you maintain an efficient roof water drain and protect your investment for years to come.

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