Pond On Your Flat Roof? Simple Steps To Correct Your Drainage Issues


While commonly associated with commercial buildings or industrial warehouses, many homeowners are seeing the benefits of their flat roof.  Not only are they easy to clean due to their sturdy, horizontal foundation, but they are also inexpensive to maintain. Unfortunately, your flat roof may be holding water due to improper construction. Known as a ponding roof, the excess water can lead to mold, algae, and leaks in your roof if left untreated. If you have standing water, it is important to understand the cause and the best drainage options.

Ponding 101

Although considered flat, proper construction requires a slight incline of at least 1/8 inch per foot. This small incline is imperative for draining rainwater and other moisture off your roof before it causes damage.

Unfortunately, tearing down your roof to rebuild can be extremely costly and overwhelming. Adding a few updates to your existing flat roof is imperative for drainage.


Adding rain gutters to your flat roofing system is an affordable and effective option for improving drainage. A traditional system uses multiple sections of aluminum gutters, but each section requires a seam. Debris and moisture will easily trap in each of these seams, blocking your gutters and preventing drainage off your flat roof.  To reduce your chances of ponding, add value to your home, and prevent roof damage, consider installing seamless gutters.

Installed in longer pieces around the exterior of your roof, seamless gutters move water off your roof and onto the ground through downspouts. While not completely free of seams, the seamless design only requires seams at downspout and corner locations. With a reduction in seams, your flat roof will have adequate drainage.

Scupper Drains

Your flat roof may also benefit from a series of scupper drains. Similar to gutters, scuppers run along the exterior perimeter of your roof.  They lead water off the side of your roof, over a flashing, and down through a customized downspout.

Constructed from copper, aluminum, or galvanized metal, they are one of the most inexpensive options for improving the drainage of your flat roof.

Internal Drains

If you frequently see ponding on your flat roof, installing an internal drain system is a worthwhile investment. Connected to pipes that run through your house and into your local storm sewer, they effectively remove water from your roof.

Internal drains also offer a strainer on each side of the roof. These strainers collect leaves, dirt, and other debris before running off the roof. Preventing this debris from entering the sewage system benefits the environment, as well.

As a homeowner, you most likely understand the importance of a proper roofing system. For your flat roof, prevent or correct ponding issues using this guide. For more information and advice, contact a professional roofing company like Rainbow Gutter Co.