The Fundamentals of Roof Accessories: What Are Rooftop Curbs?
Rooftop curbs are raised metal frames designed for mounting structures safely to your roof. The frames are used for accessories that mount above the roof and those that penetrate the roof’s surface. A properly installed roof curb ensures that the accessory has a level platform for attachment. They also can be clad with flashing to prevent unwanted water damage from seepage through the roof’s membrane.
What Are Some Uses for Rooftop Curbs?
Common applications are:
- Hatches — Hatches provide a means of accessing the roof. Design Components, Inc., offers BILCO hatches, which integrate with our roof curbs, METALWALK® rooftop walkway system, and various OSHA-compliant ladders.
- Skylights & smoke vents — We offer skylights, smoke vents, and combination assemblies that let both light in and harmful gases out. Regardless of the model, a roof curb is used to mount the assembly so that it sits securely and the hole through the roof is protected.
- Exhaust fans — Roof ventilator assemblies need to push air from ducts inside the building through your roof’s membrane into the open air. To mount up-blast fans, an all-welded curb cap fits over an appropriately sized roof curb.
- HVAC units — Condensing units for HVAC systems need to sit above the roof on secure and level platforms. Our roof curbs are the foundation of condensing support units that provide a stable base to secure your equipment and protect your investment.
What Are Rooftop Curbs Made Of?
Design Components, Inc., offers roof curbs fabricated in three different metals:
- Galvalume — 18- and 14-gauge sheet steel coated with a 55% aluminum and zinc alloy.
- Galvanized Steel — 18- and 14-gauge steel coated with zinc to resist rusting.
- Aluminum — .080- and .063-inch thick aluminum sheets.
No matter which of the above materials you select, a durable seal and effective insulation are requirements. We use standard 1.5-inch thick, 3-pound density fiberglass insulation with continuously welded seams for our rooftop curbs. We also weld water diverters, known as crickets, into the construction. Our Design Components, Inc., rooftop curbs are backed by a 20-year manufacturer’s warranty. We also offer adapter curbs if you need to retrofit existing installations.
Planning for Rooftop Curbs: What Do You Need to Know?
Before installing roof curbs, there are many details to consider. It is important to know the pitch of the roof as well as the style and manufacturer of the roof panel. Different panels can have different profile styles and rib height requirements. Paint color can be useful to know as well since rooftop curbs can be custom painted to match your roof.
Poorly installed roof curbs can cause as much as a 30% performance loss on airflow systems due to leaks, temperature losses, or airflow losses. This is why it is important to work with professional installers with the expertise to properly mount rooftop curbs and test for points of leakage.
Essential Components for the Safety and Protection of Your Roof
Almost all commercial buildings have some combination of hatches, skylights, vents, condensers, and fans. These items all cost money, add weight to your roof, and must penetrate your roof’s membrane to do their job. Rooftop curbs are the essential component required to protect your investment in equipment, ensure safety, prevent inefficient operation, and avoid damaging water leaks.
Our team is made up of industry experts who can guide you to the rooftop curbs, accessories, and flashing suited for your unique situation. We’ll help you choose the materials and assemblies for your roof type, access points, and equipment. Questions? Please contact us or call us today at (800) 868-9910.
