A better way to lay new metal on old steel

By Jesse Sanchez. 

A company built on a dedication to quality and craftsmanship finds new ways to make old metal buildings feel safe again. 

As shared on this episode of Roofing Road Trips®, Dale Nelson, founder and president of Roof Hugger, joined vice president D.J. Highnote to discuss how a structural problem led to a new approach to metal retrofit. When Dale first began retrofitting metal buildings, the standard approach was straightforward: lay hat channel across the high ribs of the existing roof and fasten it down. It was common practice. But Dale said it was not structurally sound. “The usual approach wasn’t structurally correct,” he said. “We needed something that connected straight down into the structure below.” 

That realization led to the development of the notched Z, a structural member designed to sit over the existing metal panel and fasten directly into the purlin below. Instead of relying on the old panel for support, the system created a direct load path into the building’s framing. As a result, the roof assembly behaved differently under weight and movement. 

“After you put the Roof Hugger on, it didn’t spring anymore,” Dale said. The reduced deflection confirmed that the connection was doing more than holding panels in place. It was changing how the structure responded under load. That observation prompted further testing. 

To measure the impact, Roof Hugger constructed a 50-foot-long, two-bay test bed to evaluate how retrofit components performed under controlled conditions. The company conducted more than 30 tests across different gauges, profiles and part heights. And engineers analyzed how each variation affected strength and deflection. 

The data was then incorporated into proprietary engineering software. Rather than evaluating only purlin capacity, the modeling accounts for the entire assembly, including laps, fasteners and connections; the components that often determine where a system will fail first. 

That emphasis on understanding the full structural system continues to shape how Roof Hugger approaches retrofit projects today. 

D.J. said structural clarity remains central to metal-over-metal retrofit, especially when contractors compare it to other recover options. “When they install TPO on a metal building, they’re considering that roof panel a deck and it’s not,” D.J. said. “It’s not a structural deck.” Metal buildings are engineered for channeled water flow along panel ribs. Water is designed to move quickly off the roof while purlins and panels deflect within controlled limits. When a flat membrane system changes that profile, drainage patterns and load distribution can shift, particularly under snow or ponding conditions. 

D.J. also noted that modern metal finishes often outlast rooftop solar systems. “That metal roof is going to last twice as long as the photovoltaic panels,” he said. “And they mount externally without penetrating the roof panel.” For building owners, a structurally connected metal-over-metal system provides strength, preserves drainage performance and creates a long-term platform for future upgrades. 

Listen to the podcast or Watch the interview to learn more about Roof Hugger and how retrofit testing shapes stronger metal roofs for long-term performance!