Proper roof drainage is essential to avoid expensive repairs and keep your building structurally sound. On flat or low-slope roofing systems, this often overlooked key part is the roof scupper, which prevents water from pooling on flat roofs and causing damage.
In this blog post, we’ll explore what roof scuppers are, why they matter, and how they help protect your building.
What Is A Roof Scupper?
A roof scupper is a type of drainage system used to efficiently control water runoff on flat or low-slope roofs. It permits water to exit the roof via a cutout channel that is shaped slightly like a box, directing water into the downspouts. It keeps water from ponding on the surface of a low-slope roof and guards against harm to the roofing membrane and structure.
Typically, they are square or rectangular holes drilled through the roof’s edge or parapet wall and positioned at the lowest points of the roof to allow for adequate drainage. Giving a seamless and visually appealing look, they seem to be a natural part of a building’s design and are made of sturdy materials like metal such as copper, aluminum, or stainless steel.
There are two different types of roof scupper:
- Channel-Type Scuppers: These have three open sides and stick out from the building. Made from durable materials like copper or stainless steel, they are used on flat roofs to direct water off the roof into the downspouts, but can easily be blocked by leaves and debris.
- Through-Wall Scuppers: These have rectangular openings from the roof through the wall. Made from TPO, PVC, or metals, they effectively direct water away through the wall structure.
Why Is A Roof Scupper Important?
1. Water Drainage and Prevention of Water Damage
- Effective Water Discharge: Roof scupper drains remove water from flat or low-slope roofs efficiently, preventing water accumulation and potential damage.
- Minimized Risk of Leaks and Structural Problems: Scuppers facilitate rapid water runoff, reducing the likelihood of leaks and structural damage caused by stagnant water.
2. Interior Protection and Maintenance
- Interior Preservation: Roof scuppers redirect water away from a building’s interior, safeguarding against water intrusion, mold formation, and damage to interior surfaces and assets.
- Reduced Maintenance Needs: Properly installed scuppers can reduce the frequency of roof maintenance by efficiently directing water away from the roof.
3. Structural Integrity and Compliance with Building Codes
- Preservation of Structural Stability: Roof scuppers aid in maintaining the structural stability of buildings by minimizing the accumulation of excess weight from water, which can weaken roofs over time. There are also large scuppers to prevent debris accumulation and maintain larger amounts of water.
- Adherence to Building Codes: Including roof scuppers in the drainage system helps comply with building codes and regulations regarding adequate drainage.
4. Aesthetics and Design Flexibility
- Architectural Integration: Roof scuppers can seamlessly blend into various architectural styles, providing both functional drainage and enhanced appeal.
- Versatile Design Options: Scuppers come in different shapes and configurations, such as open, through-wall, and decorative round designs, catering to specific architectural requirements.
5. Economic Benefits
- Cost-Effectiveness: Roof scuppers offer cost-effective drainage solutions, requiring minimal maintenance and straightforward installation.
- Increased Property Value: Proper drainage via scuppers can increase the value of a property by maintaining structural integrity and preventing damage.
How To Install A Scupper On A Flat Roof
This is a brief guide on how to install a scupper on your flat roof. Keep in mind that you should only attempt to install one yourself if you have previous roofing experience and the right safety measures in place. If not, a professional is always the best choice for scupper installation
Preparing the Scupper
- Trim the scupper to size, ensuring it exceeds the parapet wall opening by at least 2 inches
- Roughen the scupper surface using sandpaper to promote better adhesion
- Apply a suitable primer to the scupper to strengthen the bond with the roofing membrane
Installing the Scupper
- Align the scupper within the parapet wall opening, ensuring it is level
- Secure the scupper in place by nailing its flanges to the wooden block every 3 inches
- Seal all connections between the scupper: conductor’s head (if present), downspout, fascia, and gravel stop using solder
Applying the Roofing Membrane
- Lay down a self-adhered base layer, like a mid-ply membrane, extending 6 inches beyond each side of the scupper
- Torch down the initial layer of the roofing membrane up the parapet wall, ensuring a tight seal around the scupper
- Torch down the second layer of the roofing membrane down the parapet wall, overlapping the first layer by at least 6 inches
- Apply a compatible mastic around the scupper to seal gaps and offer additional protection
Overflow Scuppers
- In regions prone to severe ice, snow, or debris, install conductor heads that help with an overflow of water
- Position overflow scuppers higher than regular flat roof scuppers to prevent water accumulation on the roof if regular scuppers become obstructed
Also Read – How Long Does A Flat Roof Last?
Roof Drain vs. Scupper: What Is The Difference?
The big difference between a roof drain and a flat roof scupper is how they carry water off of the roof. A roof scupper sends water down a metal edge, wall, or deck and into a downspout outside, while a roof drain carries water through a series of pipes within the building before letting it out. water through pipes inside the building before it goes out.
Roof drains are made to stop debris from clogging the pipes, which scuppers can’t do. Also, scuppers might freeze in winter since they’re located outside, unlike roof drains that stay warm inside. To put it simply, both options have their pros and cons, but what really matters is your budget and the climate in your area.
What Are The Maintenance Requirements For A Roof Scupper?
Maintaining roof scuppers is essential for effective water drainage and preventing damage. Follow these steps:
1. Regular Inspections:
Check scuppers twice a year, especially after bad weather, for clogs, debris, and signs of wear or damage.
2. Cleaning:
Regularly clear debris from scuppers and downspouts to maintain proper water flow.
3. Check Seals:
Ensure seals around scuppers are intact and not worn out to prevent leaks.
4. Strainers and Shields:
Install strainers or shields to keep debris from clogging scuppers.
5. Water-Resistant Coatings:
Apply water-resistant coatings to enhance scupper durability.
6. Ensure Proper Installation:
Ensure scuppers are correctly installed, considering alignment, weather, and roof pitch for efficient water flow.
7. Get Professional Assistance:
Consult a roofing expert if unsure about maintenance or if significant issues arise.
Choosing the Right Roof Scupper for Your Building
Proper flat roof scupper installation is crucial for effectiveness and durability. The International Plumbing Code (IPC) outlines guidelines for placement, size, and construction, ensuring compliance and performance.
Design and Aesthetics:
Consider the scupper’s design and its integration with the building’s architecture. Some serve purely functional purposes, while others enhance aesthetics. Opt for a design that complements the building’s style while ensuring efficient drainage.
Sizing and Placement:
- Roof Area: Larger roofs may necessitate multiple scuppers or larger openings.
- Rainfall Intensity: Assess local climate and rainfall patterns to determine size requirements.
- Building Design: Position scuppers strategically to effectively divert water from the building.
Prevent Ponding Water With The Team At All Around Roofing, Siding & Gutters
Overall, roof scuppers are vital for channeling water away from flat or low-sloped roofs, preventing water damage, and protecting the building’s structural integrity. To get the most reliable gutter installation, maintenance, and repair, contact our team at All Around Roofing, Siding & Gutters. We provide peace of mind with our expert gutter services. Call us at (937) 902-2839 to learn how we can help you!
