Have you ever thought about where all the rain goes when it begins to pour down on your flat roof? Most people don’t realize how important roof drainage systems are for protecting properties from water damage. A good roof drain system moves water away from your building, stopping leaks, rot, and creating the need for costly repairs. However, not all roof drains are the same.
There are different types to choose from, depending on your roof, climate, and budget. In this blog post, we’ll look at the most common roof drains, their pros and cons, and help you find the best option for your needs.
4 Best Types Of Drain On Roof
If you have been looking for roof drains for your flat roof, we have curated a list of the top flat roof drain options that you can choose from:
#1. Interior Drains (Central Roof Drains)
Interior drains are placed in the lowest spots of flat roofs to collect rainwater. Using hidden pipes, they move water away and keep the drainage system protected from debris. Regular cleaning is essential to prevent clogs. This design blends well with the building’s look while ensuring effective drainage during heavy rain.
| PROS | CONS |
| Aesthetically pleasing and discreet | Installation can be more complex than external systems |
| Protects drainage systems from external debris | Vulnerable to leaks if not installed correctly |
| Reduces ice formation risk in colder climates | Higher initial construction costs |
#2. External/Scupper Drains
Scupper drains are openings at the edges of flat or low-slope roofs that let rainwater flow off. Extending out past the roof slightly, they help direct water away from the foundation and can be integrated into parapet walls. They are easy to maintain but need regular cleaning to avoid blockages from leaves and debris.
| PROS | CONS |
| Facilitates straightforward maintenance | Can freeze in colder climates, causing blockages |
| Reduces the risk of standing water on flat roofs | May struggle with heavy rainfall without additional support |
| Versatile for various building designs | Limited effectiveness in heavy snow conditions |
#3. Siphonic Roof Drain
Siphonic roof drains use negative pressure to quickly remove large amounts of water from flat roofs without relying solely on gravity. They have fewer drain outlets than traditional methods, allowing for efficient layouts during heavy rain. However, they require precise engineering and regular maintenance.
| PROS | CONS |
| Highly efficient at quickly removing large volumes of water | Higher initial costs due to specialized components |
| Fewer outlets reduce installation complexity and costs | Vulnerable to blockages without proper design and maintenance |
| Aesthetically pleasing by minimizing visible plumbing | Potential pipe failure risk under extreme conditions |
#4. Roof Overflow Drains
Roof overflow drains activate when primary drainage systems fail, preventing flooding on flat roofs. They allow excess water to escape safely, protecting the structure during heavy rain. These drains should be paired with primary systems for effective stormwater management.
| PROS | CONS |
| Helps prevent structural damage from excess water weight | Not a standalone solution; it relies on primary drains |
| Minimal maintenance is required once installed correctly | Risk of clogging if not maintained alongside primary drains |
| Integrates easily with existing drainage systems for efficiency | Limited effectiveness in extreme weather without adequate support |
What Materials Are Roof Drains Typically Made From?
To get the best for your roof drain, consider getting your roof drains in the following materials:
A. Cast Iron
Strong and durable, it resists rust and prevents clogs, perfect for areas with heavy rainfall.
B. Stainless Steel
Highly resistant to corrosion, great for tough weather, and low maintenance.
C. PVC
Lightweight, affordable, and easy to install, it prevents debris buildup and ensures smooth water flow.
What Is The Difference Between Roof Drains And Gutters?
Roof drains and gutters manage water runoff in different ways. Roof drains are used on flat roofs to collect water at specific points and direct it into internal pipes, preventing pooling. Gutters on sloped roofs channel rainwater into downspouts, guiding it away from the foundation. In short, drains handle water accumulation, while gutters control the flow of runoff.
Tips To Maintain Roof Drains
Property owners need to choose the right type of roof drain, but even with the right type, it is also important to properly maintain them for proper functioning. Here are some points to keep in mind:
1. Inspect Regularly
Check your roof twice a year, especially in the fall, for damage and drainage problems.
2. Ensure Drainage Flow
Confirm drains, scuppers, and gutters are clear and sloped correctly for smooth water flow.
3. Prevent Ice Dams
Watch for ice dams forming along the roof’s edges, which can block drainage and lead to leaks.
4. Check Insulation
Ensure proper insulation to minimize heat loss and help prevent ice dams.
5. Get Professional Help
If access is difficult or issues persist, consider hiring a roofing pro for assistance.
Do Different Climates Affect The Choice Of Roof Drain Type?
Yes, climate plays a big part in choosing the right type of roof drain. In regions with heavy rainfall, siphonic drains are preferred because they efficiently handle large volumes of water. Areas with moderate rainfall may rely on standard drains, while colder climates often need internal drains that are protected from insulation in order to prevent ice buildup.
In windy locations, scupper drains can help manage wind-driven rain effectively. Additionally, local building codes, which reflect historical weather patterns, often include specific drainage requirements.
Discover The Right Roof Drain For Your Building With OConnor Contracting
Selecting the right roof drainage system is key to protecting your building from potential water damage. By understanding the different types of roof drains, you can make an informed decision that ensures your building remains well-protected and functions efficiently.
Don’t let your roof drain your wallet! Our team at OConnor Contracting provides expert flat roofing services, including installations, repairs, and maintenance for your roof drain. With years of experience, we ensure your flat roof drainage system is in excellent condition, protecting your property from water damage and saving you money over time. Contact us today at (716) 600-7663 for an instant quote!
