You already know what a roof is. And, you already know what a curb is. But, do you know what a roof curb is?

In the commercial roofing industry in particular, roof curbs are essential to the overall functioning of the complete roofing system. Used on virtually all flat roof types—from TPO to EPDM and Modified Bitumen—roof curbs are critical to protection of both the roof itself and rooftop-mounted appliances like HVAC equipment, stovepipes, and other hardware.

Because of how integral roof curbs are to the success of any commercial roofing project, the roofing professionals at A-to-Z Roofing & Exteriors have teamed up to bring you the low-down on roof curbs: what they are, how they work, and why they matter to commercial roofing installations and repairs.

Roof Curbing: Why It’s Needed

Any time there is an engineered opening in a commercial roof, there will likely be the need for a roof curb.

It can help to think of a roof curb (also called ‘roof curbing’) as a kind of industrial-grade spacer that acts as a barrier between a commercial rooftop opening and the protective layers of the roof itself.

When we think about the many different reasons why a commercial roof might need an engineered opening, we might think of:

  • Heating, ventilation, or air conditioning ducting
  • Chiller intakes/exhausts
  • Evaporative cooling equipment
  • Stovepipes
  • Skylights
  • Chimneys

Essentially, wherever a portal needs to be supported in a commercial roof, a roof curb plays the role of providing support to the installed equipment (i.e., HVAC unit) while also maintaining a fortified barrier between the building and the exterior environment.

roof curb install

Because roof curbs need to be strong enough to support potentially thousands of pounds of industrial equipment, they’re often composed using galvanized steel of at least 14-gauge thickness. Roof curbs are manufactured by numerous companies both international and domestic.

Different Types of Roof Curbs

There is no one-size-fits-all roof curbing solution for every commercial rooftop in Colorado. That’s why it’s important for a commercial roofer to know how to integrate roof curbs into a wide variety of rooftop-mounted equipment.

A-to-Z Roofing & Exteriors has the ability to source and install customized roof curbs that provide seamless protection and durability for decades.

Some of the more common roof curb products used on rooftops in our state include:

  • Pipe curbs. Pipe curbs are typically 14”-tall and come with or without integrated boot pipe penetration systems.
  • Metal roof-specific roof curbs. Metal roofs have unique requirements for roof curbs. Many roof curb manufacturers sell custom-fabricated Galvalume roof curbs that easily install onto existing metal roof support structures.
  • Vibration-isolating roof curbs. Specifically used for dampening the vibrations that come off industrial HVAC equipment, vibration-isolating roof curbs make use of specially designed suspension systems that reduce the transmission of noise and rattle.
  • Insulated roof curbs. Here in Colorado, insulated rooftop curbs are highly recommended! These roof curbs often use 3-pound density rigid insulation to offer enhanced protection from the cold in the cooler months and the heat in the warmer months.
  • Platformed/catwalk roof curbs. Sometimes, heavy-duty roof curbs are needed to support platforms that are used for the installation of power transformers or other heavy equipment. In these cases, a gusseted roof curb with a sufficient load rating is needed.

It’s common for roof curbs to be replaced or restored during a complete commercial roof replacement. However, this may not be needed in every case.

Also, when the time comes for new rooftop units (example: ventilators or swamp coolers), roof curbs might need to be replaced with curbs that are specific to the rooftop unit model being installed. However, this isn’t always true; sometimes, a curb adapter can be used on top of the existing roof curb.

When to Replace Roof Curbing

It’s common for leaks to develop around roof curbing, as it’s an area of vulnerability that can be compromised as environmental factors degrade roofing materials and allow water to penetrate the roof opening.

In Colorado, roof curbs take a beating over time due to extensive UV exposure, wild temperature swings, and heavy precipitation. For this reason, it’s important to have roof curbs inspected at least once a year. Any sign of warping, deteriorating adhesive, or corrosion should be promptly addressed by a professional roofer with experience in commercial applications.

Have questions about roof curbs? Or, do you think your commercial roof might be in need of a proper inspection performed by a trained roofing technician? Contact A-to-Z Roofing & Exteriors today, and we’ll be happy to help!