When rooftop installations require structural support—but you want to avoid roof penetrations—equipment supports are the solution. These versatile, load-bearing components are designed to elevate and support HVAC equipment, piping, ductwork, walkways, and more, all while protecting the building’s roof structure.
What Is an Equipment Support?
Equipment supports (also known as equipment rails, support rails, or sleeper curbs) are structural, roof-mounted components used to distribute weight evenly across the roof surface. They are commonly used to support:
- Rooftop HVAC units (RTUs)
- Ductwork
- Piping
- Walkways
- Power exhaust modules
- Supplemental rooftop accessories
These supports are typically constructed of galvanized steel with continuous welded, mitered corner seams for strength and durability. A protected wood nailer beneath the galvanized cap allows roofing material to be securely attached when required.
Equipment supports are available in various heights and lengths, allowing them to be customized for specific project requirements. They are easy to transport and can be carried directly onto the roof without special equipment.
Not All Equipment Supports Are Created Equal
The quality and design of equipment supports vary significantly between manufacturers.
Linear Weight Distribution (MicroMetl’s Advantage)
MicroMetl-style equipment supports provide linear weight distribution, spreading load evenly across the full surface of the support. This reduces point-loading stress on the roof system and helps prevent:
- Roof membrane damage
- Roof sagging
- Structural wear
The Risk of Point-Load Designs
Some manufacturers use designs that rely on only two legs or posts to support the load. This creates concentrated pressure at each point of contact. The smaller the surface area, the higher the static loading.
A helpful analogy:
A 100-pound person wearing high heels can exert close to 1,000 pounds per square inch on a stiletto heel—with as little as 1/10 of a square inch of contact area. The same principle applies to point-load equipment supports.
Common Applications
Power Exhaust Modules
Aftermarket power exhaust systems are often attached to RTUs using screws alone. Over time:
- Vibration
- Weight
- Torque
…can cause separation from the RTU, resulting in air leakage, water intrusion, and reduced performance. An equipment support placed beneath the power exhaust redistributes load and stabilizes the assembly.
RTUs That Extend Beyond the Curb
Some larger RTUs (25 to 100+ tons) overhang the roof curb, requiring additional structural support. In these cases, equipment supports help carry the extended load and meet manufacturer guidelines for proper installation.
Can I Reuse an Existing Equipment Support?
The answer depends on the design and condition of the existing support.
Most installed supports:
- Are shorter than the roof curb
- Extend wider than the curb beneath the RTU base rails
- Are not height adjustable
When using a MicroMetl curb adapter, adjustable equipment supports with ½” neoprene base pads can be positioned directly on the rooftop without attaching roofing material. In cases where an existing support is usable, an engineered placement plan ensures proper load transfer.
Always evaluate the condition, alignment, and structural suitability of any existing support before reusing it.
Don’t Substitute Quality
Equipment supports are engineered components designed for structural reliability. Improvised substitutes—like dunnage, railroad ties, or untreated wood—might seem cost-effective, but they come with significant risks:
- Rot
- Termite and insect damage
- Moisture absorption
- Compression over time
These materials are not designed to withstand long-term load or weather exposure.
Standard vs. Canted Equipment Supports
MicroMetl-style equipment supports are available in two configurations:
Standard (Straight) Supports
Flat, horizontal supports designed for level rooftop applications.
Canted Supports
Angled designs that match sloped rooftop surfaces or specific roof conditions.
Both types are engineered for 200 lbs. per linear foot of load support, providing robust, uniform stability.
