Behind every terabyte processed and workload deployed is a framework of precision-engineered steel. One of the most important choices you’ll make is how that framework routes power, cooling, and cabling.
Modern data centers face GPU-heavy racks that can exceed legacy 1,200 lb limits, rising thermal loads from AI, stricter seismic requirements, and almost zero tolerance for downtime. The question isn’t simply choosing between a raised-floor and an overhead system. It’s deciding which approach fits your facility’s mix of cooling efficiency, structural load capacity, and accessibility.
Whether you're building a new facility or retrofitting around existing support infrastructure in your data center, the precision of your components ultimately determines system performance. This guide compares both architectures and explains how roll-formed components support the structural integrity of both options.
For decades, the raised, underfloor design was the standard infrastructure design because it creates a dedicated plenum for cooling and hidden pathways for cabling. However, as server density increases, overhead systems have gained popularity for their flexibility and airflow benefits.
Here’s how the two approaches compare across critical engineering factors.
Raised Floor (underfloor): This traditional method pumps cold air into the plenum under the raised floor, pushing it up through perforated tiles in front of server intakes.
Overhead (Above Rack): Overhead systems often utilize hot aisle/cold aisle containment, dropping cold air from above or exhausting hot air upward.
By reducing obstruction, overhead designs allow cooling systems to operate at peak efficiency with less energy expenditure.
Raised Floor: While aesthetically pleasing because cables are hidden, maintenance can be difficult. Tracing a specific cable often requires lifting heavy floor tiles, which can disrupt plenum pressure.
Overhead: Overhead cable trays provide immediate visual access. Adds, moves, and changes are significantly faster and less disruptive to the facility's cooling.
For overhead systems, you need lightweight, but rigid channels. Roll forming is ideal for manufacturing long, continuous cable trays and wire raceways with pre-punched holes for easy installation.
This is perhaps the most pressing issue for modern facilities. Legacy racks were not designed for the density of today’s AI-driven workloads.
Roll-formed hat channels and box beams are often used to reinforce server racks, boosting capacity by 20%-30%. This “bolt-on” solution allows you to meet modern seismic codes like IBC/OSHPD without the downtime of a full rack replacement.
This approach extends the lifespan of your current infrastructure while accommodating heavier, next generation hardware.
Regardless of whether you choose a raised floor or overhead infrastructure, the integrity of the system relies on the manufacturing process of the steel components.
Why roll forming? It’s the optimal method for producing the long, slender, and repeatable metal profiles required for data centers.
In a data center, a gap of a fraction of an inch in shielding or framing can lead to thermal leaks or EMI interference. Roll-formed parts offer repeatable tolerances up to +/- 0.005” on profile segments. This ensures that when you install roll-formed steel channels for servers, the rails align perfectly every time, preventing jammed slides or misaligned connectors.
Supporting overhead trays or reinforcing racks requires high yield strength. Roll forming efficiently processes High Strength Low Alloy (HSLA) steel. This allows manufacturers to use thinner material gauges to reduce weight while maintaining the necessary structural strength.
Understanding structural steel mechanical properties is vital when specifying components that must bear static loads for decades without deforming.
Speed of deployment is a competitive advantage. Roll forming allows for features like holes, notches, and embossments to be punched in-line during production.
Ultimately, components that are easier to assemble translate directly to reduced labor costs and faster time-to-commission.
The debate between raised floor and overhead designs will continue as server technologies evolve. However, the need for strong, precise, and scalable support infrastructure is constant.
By utilizing roll formed components, engineers can ensure their facilities can handle the weight, heat, and power demands of the future. Are you ready to strengthen your data center infrastructure? Discuss how custom roll formed components can support your next project and talk to a Dahlstrom expert.