License Number:

State: RC29027654

County: U22314

BBB Rating A+

Niks Roofing Logo

How Does A Flat Roof Drain

If you’ve ever considered a flat roof, you might have wondered: how does a flat roof drain?

Flat roofs may appear deceptively simple, but flat roof systems are actually quite complex. To create this type of roof, the slope must be engineered in such a way as to make it appear flat even while ensuring efficient water drainage. Several drainage options exist and can make all the difference between a functional flat roof and a disaster waiting to happen.

Photo by Kelly urban lamscape, flat roof

Scuppers, crickets, central roof drains and gutter systems are popular flat roof drainage options that allow water to get off safely and quickly.

When choosing materials or hiring a contractor for flat roof installation, it’s essential to ensure that they understand the various flat roof drainage methods so that your flat roof will last for years without any rain-related complications.

Why Is Draining Essential?

Drainage is a critical component of flat roofing.  It can help keep your flat roof in top shape for years to come. Whether you’re looking for a solution for an existing flat roof or incorporating drainage into a new construction build, it is an important component of keeping the flat roof surface dry, clean, and safe from potential damage.

Using flat roof drainage systems, water can be directed away from the roof surface and into gutters. It diverts moisture away from vulnerable areas such as seams and helps protect your flat roof integrity over time.

Flat roofs with proper drainage are less susceptible to water damage in rainy climates and require less maintenance overall and allow you to enjoy all the benefits of having a flat roof in your home.

Interior Drains: An Additional Layer of Defense

Large buildings frequently have this kind of drainage system installed on their rooftops, although private dwellings can also use them. Imagine them as the drain in your shower or sink. 

To keep water from the house’s foundation, they use an internal network of pipes located below the roof. The center of the roof is normally where the drains are located.


  • Interior drains add an additional layer of defense that can lessen floods’ consequences and water damage.
  • By diverting water away from the foundation, interior drains can assist in maintaining the dryness of basements or crawl spaces.
  • Since interior drainage systems are frequently simpler to build than external drainage systems, homeowners can save money by using them.
  • Since moisture buildup may be avoided with the right precautions, some interior drainage systems can aid in reducing mold growth.


  • When removing a lot of water, inside drainage systems fall short of outdoor drainage systems.
  • They may cost more to install and maintain than outside systems like French drains or sump pumps.
  • Interior drainage systems need routine maintenance because clogs can form in the drain pipes and cause backups and flooding in your home’s basement or crawl area.
  • Your home’s foundation must be accessible to install an interior drainage system, which occasionally calls for additional excavation work.

Scupper Drainage System

Large flat roofs typically have scuppers or large square apertures near the roofline where water can escape. This sophisticated form of flat roof drainage ensures that water won’t build up on the flat surface and flow back into the building.

To control water outflow, there’s usually a downspout connected underneath the aperture designed to collect and direct the water away from the building. So it makes sense to install scuppers on flat rooftops to ensure solid protection in terms of flat roof drainage and defending your building against potential floods.


  • Scuppers are the finest option for effectively draining water from a flat roof when it is appropriate.
  • It is a simple, low-cost system that rarely clogs and is straightforward to maintain.
  • It improves any building’s architectural appeal.


  • Might quickly become overwhelmed during a strong downpour.
  • Require periodic upkeep to ensure proper operation.
  • Can develop obstructions from garbage, leaves, and other items, causing water to collect on the roof.

Gutter Drainage Systems

Gutters are the most widely employed method, acting like the ones on sloped roofs. They use their low profile to skilfully channel rainwater away from your flat roof into a downspout and away from your property’s foundation.

They have many advantages, including safeguarding each layer of the flat roof covering and improving the aesthetics of flat roofs by increasing consistency. Therefore, it’s crucial to consider flat roof guttering designs from a functional and aesthetic standpoint.


  • Increases the curb appeal of your property 
  • Aids in preventing soil erosion and water retention in the yard
  • Protection against water damage to your home’s exterior walls and foundations 
  • Easy access for clearing off accumulated leaves and debris
  • Redirects water away from outdoor furniture, decks, and paths to make them safer.


  • Expensive and labor-intensive to install correctly
  • It may need regular maintenance and cleaning to remain effective
  • Clogged gutters can cause water damage to the roof and other parts of your home 
  • Increase the chances of clogged downspouts due to the accumulation of leaves and debris
Nik's Roofing Infographic about 2 types of flat roof drain

Central Roof Drains

On the commercial roof, central roof drains, often known as “inside drains,” are common. Roof crickets or the roof’s natural slope are employed to send water to these drains located in the middle of the roof.

For really big roofing systems, these drains are a particularly wise choice. They connect to pipes that safely transport water down and out of the building through its roof.

These drains are also a fantastic alternative for colder climates since, because the insulation of the building shields them, they are less susceptible to freezing and cracking during the winter.

How to Maintain Proper Drainage

  1. Inspect and Clear Clogged Drains: Regularly check drain pipes and remove clogs or obstructions to ensure the water drains correctly.
  2. Install Rain Gutters and Divert Stormwater: Rain gutters and downspouts effectively divert stormwater away from the home. Also, consider grading your landscape so rainwater floods away from your home.
  3. Conduct Regular Maintenance for Irrigation and Gravity-Fed Drainage Systems: Ensure all irrigation systems, gravity-fed drainage systems, and retaining walls are properly working to prevent flooding or soggy soil.
  4. Pose Proactive Flood Prevention Measures: Preemptive measures such as utilizing floodwalls or sandbags near homes prone to flooding can help minimize or prevent flooding altogether.
  5. Utilize Catch Basins: Installing catch basins at areas of low lying points along your yard will help collect standing water and route it toward a storm drain system, helping keep the drainage in check.
  6. Add Barrier Soaks & French Drain Pipes: If you have consistent overly saturated soil on your property, consider installing barrier socks or french drain pipes to intercept water flowing into saturated soils and instead direct it.


How Water Can Cause Roof Issues?

Guarantee how much water our roofs encounter. It is almost a given that they will eventually experience issues due to continuous exposure. But did you know that a flat roof drain’s effectiveness could significantly impact how long your roof lasts?

Every time it rains, high points on a flat roof can create a “water pooling” effect that can fast cause sizeable amounts of water to accumulate and remain on top of the roof. As a result, the waterproofing materials may go through unnecessary stress and pressure, suffer damage, or even break.

How Often Should a Flat Roof Drainage System be Maintained? 

Regular maintenance is essential for flat roof drainage systems to perform their intended function. Ideally, flat roof drainage systems should be checked annually for any debris build-up or corrosion, especially in areas with high snow levels and rainfall.

Cleaning and removing blockages from your flat roof drainage system will minimize the chance of flooding or water damage caused by pooling water on flat roofs. And ensuring that you remain safe while prolonging the lifespan of your flat roof.

Call a professional immediately away if you think your flat roof drainage system may be obstructed; they will have the necessary equipment and knowledge to keep it in good working order.

What Are the Benefits of a Flat Roof Drainage System? 

A roof drainage system offers both homes and businesses some advantages.

First, your roof is protected from harm brought on by significant water accumulations by having runoff from storms, snowfall, and rain collected in one area. A flat roof drainage system also lessens the possibility of water collecting, which can lead to leaks and the deterioration of the roofing materials due to prolonged periods of wetness.

This not only makes your roof safer and more secure, but it also extends its lifespan and reduces the need for maintenance and repairs. Overall, establishing a drainage system for a flat roof is a good approach to safeguard your roof and the structure underneath it while bringing you long-term peace of mind.

Does Your Flat Roof Need Better Drainage?

Your flat roof needs to be properly drained, and we at Nik’s Roofing are aware of this. Water can build up on your flat roof without proper drainage, which can result in significant damage.

Nik’s Roofing can simply evaluate the current drainage system of your home to see if it is enough for shielding your flat roof from any dangers. To guarantee that your flat roof will stay in good shape all year long, our dependable team of experts is available to install new drainage systems.Get the greatest protection for your house by getting in touch with Nik’s Roofing today. Learn more about our flat roof services.