Many commercial roofs are flat, which makes a drainage system necessary as standing water can cause severe damage to a roof. There are many different types of commercial roof drains, so it is important to explore your options to find out which one is ideal for your business.
The Importance of Drain Systems
Before diving into the different types of drain systems, it’s important to understand why a drain system is necessary in the first place. Drains take channeled water and carry the water off of the roof, which helps to protect against both exterior and interior damage.
If you don’t have a drain system, water collects on the roof, breaks down the barrier membrane and eventually seeps inside. If this happens, it can lead to costly repairs to fix not only the roof but also the inside of the building. Since leaks can cause small problems like water stains, peeling paint and mold, as well as big problems like product or inventory damage and operational setbacks, it’s important to have proper drainage systems on your property.
The Two Main Forms of Drain Systems
When you choose a roof drainage system, be aware that you have two main options to consider:
- Gravity: This system works with gravity to allow water to flow off the roof. Differently sloped segments all flow to one interior drain and work in tandem to carry the water off of the roof.
- Siphonic: This option does not rely on gravity. Instead, the opening of the drain is fitted with a part that prevents air from entering the drain. As a result, the interior of the drain has a lower atmospheric pressure, sucks water in and allows it to move freely without the need for a graded decline.
The Four Types of Drain Systems
There are four types of commercial roof drains that work well with flat roofs.
- Gutters: These are the most common in residential areas, but commercial buildings can also have gutters installed on the edges of their roofs to collect water on the roof and pass it into a downspout that helps water flow off the surface without touching the side of the building. For gutters to be effective, they must work with a roof that has a slight grade so the water enters the gutter freely. It is also essential to keep this drain system free of debris so that water can flow unimpeded.
- Downspouts: This roof drainage system is very similar to a gutter and is also called a roof drain leader. It works in conjunction with a scupper by carrying the water to the ground. This usually comes in the form of a pipe attached to the side of the building. The water flows from the scupper or gutter to this drainage pipe without touching the building, preventing mold, moss, and mildew from forming on the outside of the building. It also helps protect against water seeping into the exterior walls as water flows off the roof.
- Scuppers: Commercial roof drains commonly come in the form of a scupper, a channel or opening placed in the sidewalls of the roof, which acts similar to a gutter in allowing water to flow freely off of the roof. However, while a gutter travels along the side of the roof, a scupper allows water to flow through and then connect with a gutter or downspout.
- Internal Drains: Many commercial buildings have an internal drain placed under the surface of the roof to catch water. Usually, these are located where water collects the most or where there is a slight downward grade, so the center of the roof is a common drain location. It’s not uncommon to use internal drains in combination with other systems, such as scuppers.
Choosing your roof drainage system comes down to what type of drain you want, the type of drain your roof can interact with and what roofing experts advise. However, knowing the available choices can make the process less confusing.
Choose Drains for Your Drainage System
Commercial roof drains help to protect your roof from water damage by making sure water has a way of flowing off the roof rather than pooling on the surface. If you need to add a drain to your commercial building or want to improve your existing drainage, work with a roofing expert to decide which of the drain options are best able to meet the needs of your building.