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Why You Need Good Drainage on Your Chicago Commercial Roof

When it comes to commercial roofing systems, proper drainage might not be the first thing that comes to mind. However, a roofing system\’s effectiveness plays a critical role in its overall performance and longevity. A well-designed and maintained roof drainage system is essential for protecting your building, preventing structural damage, and ensuring the comfort and safety of the building\’s occupants.

In this article, we will look at the importance of Chicago commercial roof drainage systems, how they work, and their impact on roof performance.

Why Is Drainage Important for Chicago Commercial Roofs?

The purpose of commercial roof drainage is to efficiently move water away from the roof surface and prevent it from pooling or accumulating in undesired areas. Without proper drainage, water from precipitation can collect and even stagnate on a Chicago commercial roof, leading to various undesirable outcomes.

Here are a few of the ways that drainage systems can protect Chicago commercial roofs:

Protect Against Water Damage

Water is one of the biggest enemies of any roofing system. Without effective drainage, water can pull on the roof surface, leading to leaks, deterioration, and structural damage to the building itself.

Prevent Ice Dams

In cold climates, poor drainage can contribute to the formation of ice dams, in which melting snow refreezes near the edges of the roof, causing water to become backed up. The added weight of the water and ice that is unable to escape can lead to leaks and damage to the roof structure.

Protect the Building’s Interior

Without adequate drainage, water can sometimes infiltrate the building below, damaging ceilings, walls, and electrical systems. Furthermore, it can also harm objects within the building, such as inventory, computers, furniture, etc.

Prevent Mold and Mildew

Standing water and excessive moisture on a roof can create the ideal conditions for mold and mildew growth. This could potentially pose health risks to the building\’s occupants while also causing further damage to the building itself. Additionally, untreated mold problems may actually cause the building to become uninhabitable, according to local health codes.

Extend the Roof’s Lifespan

A properly functioning drainage system is a crucial element of any commercial roofing system. Removing excessive amounts of water from the roof will help to prolong the roof’s lifespan by minimizing damage caused by moisture.

What Are the Components of a Chicago Commercial Roof Drainage System?

In order to understand how drainage adds to the longevity of a Chicago commercial roof system, it\’s important to understand the drainage system’s components and how they work together.


Gutters are troughs that collect precipitation and channel it towards the building’s downspouts, and they are typically installed along the edges of the roof. As rainwater or snow melt runs toward the edge of the roof, it drips into the gutters and flows toward the downspout, where it can be moved away from the building.


Downspouts are vertical pipes that are connected to the gutters to assist in moving the water to the ground. Downspouts typically have a horizontal pipe at the bottom that allows them to dispose of water at a safe distance from the edge of the building. This prevents water from collecting around the building\’s foundation in order to prevent flooding and structural damage.


When a Chicago commercial roof system is flat or has a very gentle slope, the building will often have shorts walls, known as parapet walls, that extend beyond the building\’s roof. A scupper is an opening or channel that runs through the parapet walls, allowing water to escape into the building\’s gutters or drainage system.

Interior Drains

Buildings with flat or low-slope roofs often have interior drains installed at low points within the roof, also known as roof sumps. These drains collect water and channel it directly into the building\’s plumbing system or another designated drainage area.

Roof Slope

The roof slope or pitch is also an important factor that contributes to the building\’s drainage by allowing water to flow naturally towards the gutters, downspouts, and scuppers.

How Do You Maintain and Inspect a Chicago Commercial Roof Drainage System?

In order to ensure the long-term performance of a Chicago commercial roof drainage system, the building\’s owner or staff should perform regular inspections and maintenance of drainage system components.

Gutter Cleaning

Gutter cleaning is especially important if the building is surrounded by trees since leaves can accumulate and clog gutters fairly quickly. Gutter cleaning should be performed at least once per year to remove obstructions from the gutters and downspouts, ensuring that water is able to drain properly.

Inspect Scuppers and Drains

Scuppers and drains should also be inspected regularly for blockages and debris. If scuppers are visible from the outside of the building, and you notice little water flowing through them during periods of heavy precipitation, this could indicate that water is pooling on the roof’s surface.

Remove Snow

If your building is in an area with strong precipitation during the winter, it may be a good idea to perform regular snow removal from the roof. A cubic foot of snow generally weighs around 20 pounds, so if you have a 2,000-square-foot building, a foot of snow on your roof would weigh approximately 40,000 pounds.

Allowing your roof to bear this kind of weight for an extended period can significantly impact its overall lifespan and lead to structural damage in the rest of the building.

Should You Have Your Roof Inspected by a Professional?

The frequency with which you should perform professional roof inspections can depend on many different factors, such as the type of roof, your climate, and the age of the building. However, it is a good rule of thumb to have your roof inspected at least twice per year.

Chicago Commercial Roof Inspections and Repair

If you own a commercial building in Chicago, Illinois, or any of the surrounding areas, then you can count on Canga Restoration for all your Chicago commercial roof needs. Whether your roof is damaged and needs to be repaired or replaced, or if you would simply like to have a roofing professional perform a detailed inspection, Canga Restoration has the knowledge and experience to ensure your roof is safe and stable.

Canga Restoration has been in the roofing business for over ten years, servicing residential and commercial roofs around the Chicago, Illinois, area. Here at Canga Restoration, we strive to complete every job with the highest commitment to professionalism and quality.

If you would like to schedule an inspection or repair for your commercial or residential roof, click here to get in touch with Canga Restoration today!

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