One of the most common issues with flat commercial roofs is water accumulation. That’s why finding effective ways to drain your commercial flat roof is critical to its long-term health.
When water does not drain effectively, it pools up and damages the roof and underlying structure.
This can be especially devastating when there is damage to the façade of the roof. This means that water gets into areas it is not meant to be in (think leaks) and then permeates throughout the rest of the roof.
This can lead to additional water damage and potential structural damage that can be dangerous for the building and its inhabitants.
Thankfully, there are a few ways to ensure the water drains from your flat commercial roof, keeping it free and safe from potential water damage.
4 Options to Drain Your Flat Roof
- Gutters
- Scuppers
- Interior Drains
- Edge Drains
Gutters
Gutter systems, one of the most commonly used solutions, are also very cost-effective drainage solutions for flat roofs.
As the water rolls off the roof’s edge, gutters catch that rainwater and then divert it down into a downspout, which dispenses the water a safe distance away from the building’s foundation.
Ultimately, this prevents rainwater from rolling off the roof uncontrollably and running down the side of the building. Uncontrolled dripping can damage things like windows, siding, and even the foundation of the building itself.
However, there are disadvantages to using gutters as the primary drainage system on a flat roof. The first is that gutters need consistent cleaning to do their job effectively.
When debris, like leaves, builds up in the gutter, it blocks the flow of water. When the debris is not cleaned out, the water builds up and then overflows, running down the side of the building.
Gutters are also very susceptible to damage from ice, severe weather, and heavy debris buildup.
These are factors to consider when looking for drainage solutions for your flat commercial roof.
Scuppers
Scuppers are perhaps one of the most effective drainage solutions for a commercial flat roof. Using this system, large square openings are made along the edge of the roof, shooting the water safely away from the side of the building.
Downspouts can also be installed directly below the openings, which catch water and drain it away from the building in a controller manner similar to the gutters.
Flat roof scuppers also have several benefits. In addition to being cost-effective, they are much easier to maintain, meaning you won’t have to clean them as you would gutters.
Those wide, large scuppers will rarely get clogged by debris, and a well-designed scupper can even enhance the overall aesthetic of the building, making it look a little bit nicer than traditional gutters would.
Like anything else, however, downspouts have downsides. If you install the downspouts above, they risk getting clogged, requiring regular checks for debris buildup. They can also be quite ineffective for heavier snowmelt and rain.
Also, scuppers tend to be less effective on a flat roof with no pitch to guide the water to the edges of the building; the scuppers have to be somewhat cleverly designed to have the best overall effectiveness.
Interior Drains
These are similar to how the drain in your sink or shower might work. These drains would be placed in the roof areas where the water will most likely build up.
The interior drains would then lead the water through a system of pipes installed below the roof. The water would travel through the pipes until it was dispensed into a gutter or downspout on the side of the building.
Using an interior drainage system has some notable benefits. The first is that the walls and foundation of the building are protected from water damage.
The second is that the pipe system is protected from damage by the roof and walls, reducing the chances of freezing or cracking.
Lastly, this type of system is highly customizable, so you can get the exact kind of system you want.
There are downsides, however. This is the most expensive option due to the nature of the installation and customization.
Additionally, any damage that does occur must be repaired by a professional roofing technician.
Edge Drains
Edge drains work just as they sound: they sit at the roof’s edge and collect the water there.
It operates very similarly to a public shower. Scupper drains are similar in that the goal is to prevent water from running down the side of the building and causing additional damage.
Edge drains are a simplistic way to divert water from running down the side of the building.
They point the water to a predetermined destination so that it can drain safely away from the building without causing any damage.
Final Thoughts on Flat Roof Drains
Whatever the solution, drains are necessary for the life of your roof. If left unchecked, water buildup can lead to substantial issues over time.
Failure to address water pooling on your flat roof system often leads to serious and expensive consequences.
As a result, be sure to get your drainage system in place and ensure it works correctly.
