A drain on a commercial roof.

The Business Owner’s Comprehensive Guide to Commercial Roof Drainage

Commercial building owners, managers, and developers know that effective commercial roof drainage is the key to a long-lasting roof. However, navigating the importance of drainage, identifying potential problems, and knowing how quickly you should remove water from your roof can be complex.

Imagine a scenario where a poorly designed or installed drainage system on your commercial flat roof (low-slope roofs) leads to standing water and debris accumulation. Over time, these issues can result in costly repairs, structural damage, and even compromise the safety of your building. No business owner wants to face these problems!

At Heidler Roofing, we believe in proactive solutions. We’re here to guide you through the intricacies of commercial roof drainage systems, their components, and their role in preserving your property. In today’s post, we’ll delve into the different types of drainage systems, their installation, and maintenance tips.

We aim to help you understand how to ensure your commercial roof drains water efficiently and effectively, protecting your investment in the long run. If you’re ready to take action now, schedule a roofing estimate with our team at Heidler Roofing. We’re here to provide cost-effective and reliable solutions for all your roofing needs.

Why Is Drainage So Important on a Commercial Roof?

A roof’s job is to protect the building from the elements. When it rains or snows, the roof collects the water. Gravity easily moves the water to the gutters on homes with pitched roofs. But with an industrial building, commercial roofs have a much lower slope, sometimes called commercial flat roofs or low-slope roofs. That’s why proper roof drainage is even more important for business owners and building managers.

Roof drainage is a critical aspect of maintaining the integrity of commercial buildings. When a commercial flat roof (most commonly called a low-slope roof among industry professionals) drains properly, it carries water away from the roof surface, preventing accumulation and potential damage. Water pooling can add unnecessary weight to your roof, threatening its structural integrity and potentially causing leaks that could damage the building’s interior.

At Heidler Roofing, we’ve seen firsthand how an efficient drainage system can prolong the life of a commercial flat roof (low-slope roof). Swiftly removing water with positive drainage reduces the risk of moisture-related issues.

What Problems Can Occur With Improper Drainage?

Improper drainage can lead to a plethora of problems for commercial roofs. Standing water is a common issue that can accelerate roof deterioration. Standing or pooling water also creates a perfect environment for water-related issues, such as birds and mosquitoes being attracted to your roof and plant growth. These issues compromise the roof structure and affect indoor air quality, posing potential health risks.

Additionally, debris can accumulate in poorly designed or badly maintained drainage systems, leading to blockages that exacerbate water pooling. Over time, this can result in significant repair costs. Additionally, it adds weight to the roof, which can overload its capacity.

Heidler Roofing’s team of experts has extensive experience in diagnosing and rectifying these issues, helping businesses avoid unnecessary costs and disruption. We ensure your drains are clear and you have a backup drain positioned higher than the main drain. If the main drains can’t get rid of the water fast enough and the level rises to the height of the backup drain, water can still safely flow out.

How Fast Should Water Be Removed from a Roof?

A drain on a commercial roof with ponding water spots around it.

The speed at which water should be removed from a commercial roof largely depends on the roof’s design and local weather conditions. However, it’s generally accepted that water should be cleared from the commercial roof surface within 48 hours of rainfall to prevent potential damage.

We design and install commercial roof drainage systems at Heidler Roofing that efficiently carry water away from the roof surface. This swift removal of water helps to prevent issues like water infiltration, structural damage, and premature roof aging.

What Are the Different Types of Drainage Systems for Commercial Roofs?

There are several types of commercial roof drainage systems, each with its own advantages. The two primary systems used are gravity drainage and siphonic drainage.

Gravity Drainage

In essence, a gravity system uses the natural force of gravity to facilitate water flow off the roof. Various slope sections converge to a single internal drain, working together to remove water from the roof efficiently. This system typically comprises four inclined drain segments linked to an internal drain that channels the water out of the building. Gravity drainage systems are ideally suited for flat or low-slope commercial roofs with a surface area of less than 150m2 per drainage point.

Siphonic Drainage

A siphonic drainage system has a baffle on the drainage points that prevents air from entering the system. Because of the lack of air, the interior of the drain has a lower atmospheric pressure, so it can suck water in and allow it to move freely without running on an incline. This design allows water to be drawn in more quickly than gravity alone, making a siphonic drainage system up to 100 times faster than a gravity system.

Also, the roof may have a smaller slope and drain properly. A building with a large roof footprint, such as an airport, mall, warehouse, convention center, or factory, is well‐suited to a siphonic system because the weight of water on these buildings is a bigger concern. If the water on these roofs does not drain fast enough, it can add significant weight to the roof. In fact, a single inch of water on a 20-square-foot roof area weighs 2,000 pounds.

Choosing the right system depends on various factors, including the size and slope of the roof, local climate, and budget. We consult with our clients at Heidler Roofing to recommend the most suitable and cost-effective drainage solution for their specific needs. Contact us today to schedule a roofing estimate to see if your drainage system performs well.

What Are the Different Components of Commercial Roof Drainage Systems?

Commercial roof drainage systems consist of several components working together to effectively remove water from the roof. Some of these components include:

Water flowing out of a downspout.
  • Interior Drain: Placed at various points on the roof’s surface, even in the center, interior drains are used to collect and channel water. They are especially useful when the roof is sloped to allow water accumulation at the drainage point. An interior drain consists of several components:
    • Dome Strainer or Cover: This mesh or filter at the top of the interior drain prevents debris from entering the drainage system. It is usually required to be at least four inches high per most building codes.
    • Flashing or Clamp Ring: This watertight ring secures the drain and strainer together around the roofing membrane, preventing leakage into the base of the drain.
    • Outlet: This part connects the drain to the pipes below.
    • Air Baffle: This prevents air from entering a siphonic drainage system.
  • Drain Basket/Dome/Strainer: Set on the drain and locked into the clamping ring. These components prevent large vegetation and debris from getting into internal drainpipes.
  • Crickets: These components are insulation formed or cut into diamond- or inverted V-shaped ridges that direct water to drains and prevent ponding between them.
  • Drain Sump Pan: These metal plates recess the drain slightly below roof level, drawing water towards drains that might otherwise be too high to be effective.
  • Edge Drains: These collect water at the roof’s edge, preventing it from running down the side of the building. They can include scupper drains, gutters, and roof drain leaders (downspouts).
  • Scupper Drains: These drainage points are on the roof’s edge, incorporated into the walls or parapet. They are part of the backup drainage system that helps the roof shed excess stormwater.
  • Gutters: These are shallow channels that collect water at the edges of the roofs. They can be used on commercial roofs, either as a complement to interior drainage or by themselves.
  • Downspouts (or Roof Drain Leaders): These parts carry water away from the scupper or drain to the ground. They are usually cost-effective and can be installed on the side of the building without altering the building structure.
  • Conductor Head: Also known as a collection box, collector head, gutter head, or scupper box, these catch basins are usually made of sheet metal and collect and channel water from the roof to the downspouts.

Regardless of the system chosen, regular inspection and maintenance are crucial to ensure that all components function optimally. We offer comprehensive maintenance services at Heidler Roofing to keep your drainage system in peak condition.

Do Drainage Systems Need to Be Insulated?

Insulating drainage systems can be beneficial, particularly in colder climates where freezing temperatures can lead to ice blockages. Insulation helps maintain the drainage system’s temperature, preventing freezing and ensuring uninterrupted water flow. While insulation may represent an additional upfront cost, it can save money in the long term by preventing costly damage caused by frozen pipes.

What Maintenance Needs to Be Done on a Drainage System?

Maintaining a commercial roof drainage system is crucial to ensure its longevity and effectiveness. Regular inspections should be conducted to check for any signs of blockages or damage. These inspections include examining the roof surface for standing water or debris accumulation, which could indicate a drainage issue. The drains should be inspected for blockages, and any strainers or filters should be cleaned regularly to ensure they do not impede water flow.

In addition to regular inspections, it’s also essential to conduct routine cleaning of the drainage system. This cleaning involves removing debris from the roof surface, gutters, and drains that could clog the system. Any necessary repairs should be addressed promptly to prevent further damage. Depending on the type of drainage system and the local climate, insulation may need to be checked and replaced as needed.

Additional checks should be performed after heavy rain or severe weather to ensure the system is still functioning effectively. Proper maintenance of your commercial roof drainage system can prevent costly repairs in the future and extend the life of your roof.

Does Your Commercial Roof Drainage System Need Attention?

Understanding and managing commercial roof drainage is crucial to maintaining the integrity and longevity of your commercial properties. From the importance of swift water removal to the various types of drainage systems and their components, there’s a lot to consider.

Perhaps you’re now realizing the potential problems that improper drainage can cause, from structural damage to costly repairs. The thought of dealing with these issues can be overwhelming and stressful. But it doesn’t have to be.

At Heidler Roofing, we offer comprehensive commercial roof drain installation and repair services. We’re committed to providing cost-effective, reliable solutions tailored to your needs. Our team of experts will guide you through the process, ensuring your commercial buildings are equipped with efficient drainage systems that protect your investment.

Don’t let the complexities of commercial roof drainage weigh you down. Contact us today to schedule a roofing estimate. Let us help you ensure your commercial building’s roof is well-protected and set up for long-term success.