The Roofing Resource Blog

The Purpose and Importance of Commercial Guttering

Tue, Dec 2, 2014 @ 09:58 AM | Perry

Commercial property owners and managers are well aware of the importance of the roofing system installed on their buildings. A poor roof will end up leaking and creating property damage. Unfortunately, owners and managers may not be aware of the true importance of the guttering system and how gutters are designed to work.

How Commercial Gutters Work

Commercial_GuttersCommercial guttering systems are normally larger than residential. While homes may use five-inch gutters, commercial designs are six-inches or larger. The roofing system on commercial buildings is larger and the gutters must handle larger volumes of water. The materials used in the manufacturing of the gutters must also be more durable to support the additional weight of the water.

One gallon of water at room temperature weighs just over eight pounds. This is considering the water is relatively pure. When debris from the roof is included, one gallon can weigh significantly more. At freezing temperature the water weighs the same, but it increases in density and decreases in volume.

In areas subject to freezing, the gutters become even more important. Water that cannot be evenly distributed away from the roof will build up and freeze. The gutter area holding one gallon of water now has room to hold more water and therefore more weight. This type of freezing damage may not be noticed immediately and can lead to significant problems later.


Just like commercial roofing installations, gutters for commercial building require professional installation by experts in the field. If gutters are not placed properly, water can run off between the roof edge and the gutter, or flow over the gutter edge straight to the foundation.

Gutter pitch is critical. Water runs downhill. The gutters must allow the water to flow correctly; an incorrect pitch will create build up before the rainfall is diverted. Anchoring is also a factor when the size and weight of the gutter and the weight of the increased water volume is considered. Without substantial support, the guttering will pull away from the building. Commercial specialists understand the different needs of commercial properties.


Commercial_Guttering_downspoutsDownspouts are used to direct the water from the guttering and away from the foundation of the building. When water is not diverted properly, erosion to the foundation and landscaping become a problem. Flooding to adjoining buildings or areas is another danger.

The size of the commercial guttering required, and the number of downspouts needed to protect a building will be calculated by the size of the roof. Additional factors may include the average rainfall pattern in the area. A location with a low weekly rainfall will not require as extensive a system as an area that receives rainfall in large volumes at one time.

A commercial roofing system is really only as good as the guttering attached to it. If the water cannot be efficiently diverted from the roof, leaking, flooding and damage will occur.


Topics: Box Gutters