How to Protect Your Facility with Proper Roof Drainage
It’s become so common in the news these days that it doesn’t even faze us anymore—a severe weather event occurs and causes catastrophic structural damage or results in injury or death. This was the case last year, when an extreme storm popped up in South Fulton, Ga., just outside of Atlanta. According to WSB TV 2 Atlanta, heavy rain in the area caused a warehouse roof to collapse. Thankfully, no one was hurt, but the warehouse was destroyed. After the storm, the scene looked like an explosion had occurred. Several doors were blown out, and pieces of concrete and roofing were lying in the parking lot. What caused the warehouse to be destroyed was a large amount of rainwater on the roof. The water didn’t drain properly and collected there, causing the roof to collapse.
If you are a facility manager, an accident like this is the last thing you want to worry about this year. In order to prevent an incident like this from happening, it’s important to understand how a commercial roof draining system should work, the different types of commercial roof drain systems that are available, and how to protect your facility from improper roof drainage damage.
Why You Need a Commercial Roof Drainage System
No matter what kind of commercial roof type you have—TPO, metal, EPDM, single-ply, cool, foam, tar and gravel, flat, or shingle—the purpose of a commercial roof drain is to remove rainwater, melting snow, and other moisture from the roof efficiently. This prevents water from accumulating, which could lead to damage. Here are a few reasons why roof drains are so important:
Prevents Ponding Water
Standing water on flat or low-slope roofs can add excessive weight and cause structural stress or collapse, such as the example presented at the beginning of this article. Standing water is a common issue on flat roofs.
Reduces Roof Leaks & Water Damage
Proper drainage prevents water from seeping through seams, cracks, or weak points in the roof membrane, which leads to water leaks and internal structural damage. Preventing leaks also ensures the productivity of your operation, preventing downtime for repairs and lost productivity.
Protects the Building’s Foundation
Without proper drainage, water can overflow and damage parts of your facility on the ground. Your facility’s exterior walls can be impaired, and the foundation can erode. An enormous amount of water could also flood lower levels of your building.
Protects the Facility from Interior Damage
Industrial facilities often house expensive and sensitive machinery and equipment. Water leaks can lead to rust, corrosion, short-circuiting machines, and other malfunctions, resulting in costly repairs or the need for replacements.
Prevents Product Damage
If your facility stores raw materials, finished products, or inventory, leaks can also damage these goods, resulting in financial losses and potential supply chain disruptions.
Eliminates Bad Indoor Air Quality (IAQ)
Mold and mildew growth as the result of a roof leak can lead to poor IAQ. Bad IAQ can affect the health and well-being of employees and potentially result in increased incidences of illnesses and absenteeism.
Increases Energy Efficiency
Water infiltration can damage insulation, reducing its effectiveness and leading to increased heating and cooling costs. That’s because poor insulation causes facilities to struggle to maintain temperature control.
Extends Roof Lifespan
Excess moisture can degrade roofing materials over time, leading to premature wear and costly repairs.
Enhances Safety
Proper roof drainage will reduce ice formation in colder climates during the winter months. It can also prevent water overflow, which could create slippery conditions around your building.
Commercial roofs are often larger than residential roofs, requiring more materials and specialized techniques. These roofing systems must also meet higher performance standards, due to the increased foot traffic and heavier equipment loads on the roof deck.
Although most commercial roofs are flat, some facilities have sloped roofs. For sloped roofs, the drainage systems are very similar to the roof of a house; gravity does most of the work, and downspouts are often enough to carry away water. However, drainage issues can still occur. The most common drainage problem for sloped roofs is clogged gutters and downspouts. This often happens due to debris accumulation or an inadequate slope.
Flat roofs, on the other hand, require more thought when it comes to drainage systems. That’s because flat roofs are prone to water that remains standing for prolonged periods. Flat roofs also typically have components on top of them, like HVAC systems, solar panels, or antennas.
The type of roof you have—sloped or flat—will determine which roof drainage system is right for your facility.
Types of Roof Drain Systems
A drainage system should be selected based on the roof design of your commercial facility and the climate in your region. Commercial buildings use various types of roof drains to efficiently remove rainwater and prevent water damage. Here are the three main types:
Primary Roof Drains
There are three types of primary roof drains. Internal roof drains are installed at low points on the roof and are connected to an internal piping system to drain water away. Internal drains are a popular choice for commercial flat roofs. The second type of primary roof drain is a scupper. Scuppers are openings placed along the edges of the roof—in the parapet walls—that allow water to exit the roof and drain to external downspouts. Scuppers can be combined with other roof drainage systems to enhance efficiency. The third type of primary roof drain is a gutter and downspout system. This is the most common type of drain system. It collects water at the roof edges and channels it through downspouts away from the building.
Secondary (Emergency) Roof Drains
There are two basic types of secondary roof drains, which are also known as emergency drains. Overflow drains are installed slightly above primary drains to prevent roof ponding and structural damage, in the event the primary drains fail, like our example at the beginning of this article. The second type of emergency roof drain is overflow scuppers, which have higher wall openings that function as emergency outlets when water levels rise above a certain point. This process is similar to the hole in your bathtub that’s underneath the water spigot. If the water in your tub gets too high, the bathwater drains through the hole.
Specialized Roof Drains
The third type of commercial roof drains are specialized drains, and there are two kinds. Siphonic specialized roof drains use gravity and air pressure to create a siphon effect, increasing drainage efficiency with fewer pipes. This system is highly efficient and can manage large volumes of water without requiring a steep slope.
Green roof drains are designed for vegetated or “green” roofs that have plants growing on them. Green roofs are increasingly popular because of their environmental benefits. These roofs include layers of vegetation, soil, and drainage materials to manage water effectively while providing insulation and reducing urban heat. These drains permit water retention for the plants while preventing overflow.
For a commercial facility, it’s not uncommon to have more than one of the mentioned drain systems. Selecting the primary, secondary, or specialized drains that are right for your commercial facility should be based on your building’s roof design, climate, and drainage requirements.
How to Protect Your Facility from Drainage Issues
No matter what type of commercial roof you have or the drainage system that is installed, facility managers can still experience drainage issues. That’s why it’s critical to have a regular industrial roof inspection performed by a professional annually. We suggest you work with a roofing company like Capital Roof Care (CRC) that has a good reputation and is knowledgeable about positive drainage. A CRC commercial roof assessment will pinpoint small issues that can be corrected before they become a roofing emergency.
During an annual commercial roof inspection, CRC will provide a thorough assessment by checking your entire roof system for:
- Loose rivets, bolts, and other components
- Seams and cracks that could cause leaks
- Low points where water could pool
- Signs of movement
- Components, such as rooftop units and drainage systems, which might be causing issues
- Potentially damaging debris on the roof.
By having an industrial commercial roof inspection performed regularly, you can prevent structural damage, water damage, moisture-related issues, safety hazards, and destruction to inventory inside your facility resulting from improper drainage. To learn more about the benefits of proper roof drainage, view our blog titled: Rain, Rain, Go Away: The Importance of Proper Roof Drainage.
As you can see, there are several steps you can take to ensure your facility has proper roof drainage. By preventing drainage problems from occurring, understanding how a commercial drainage system should work, and the different types of commercial roof drain systems that are available, you can protect your facility. To ensure you don’t miss anything, you should schedule an annual roof assessment with a roofing professional. By taking all of these steps, you will save your commercial facility money and ensure it remains productive.
Sources:
https://strongholdroofing.com/blog/top-5-flat-roof-drainage-systems-for-commercial-properties