Some commercial buildings carry decades of deferred maintenance on their rooftops, and the older the structure, the more critical it becomes to address problems before they compound. A Lebanon building owner came to CPM ROOF with a straightforward request: install a solar ventilation fan on his third-story flat roof. What followed was a thorough assessment that revealed a roof in need of far more than just a new fan — and a scope of work that gave a 130-year-old building a 10-year warranty and a properly ventilated attic.
The flat roof was showing its age. The existing surface had oxidized and worn thin in multiple areas, the box gutters running along the roofline had begun to fail, and the attic below was relying on inadequate ventilation that had likely been insufficient for years. Once the full picture came into focus, the right solution wasn’t just a fan installation — it was a complete protective overhaul that would solve every issue at once.
What the Roof Was Telling Us
A third-story commercial flat roof takes a beating that most property owners never think about. Standing water, UV degradation, thermal expansion and contraction across seasons, and the constant stress of foot traffic during any maintenance visit all work against the membrane over time. This roof’s surface had reached a stage where patching individual problem areas was no longer a viable strategy — the entire field needed to be addressed.
The box gutters along the roofline presented their own challenge. Box gutters are built into the structure of older commercial buildings rather than hung on the exterior, which means when they fail, water has nowhere safe to go. Twenty linear feet of box gutter had deteriorated to a point where repair was essential before any coating work could begin.
Starting With a Power Wash
Before any silicone goes down, the surface has to be clean. CPM began the project with a thorough power wash of the entire roof, removing years of accumulated dirt, oxidation, and loose material that would have prevented the coating from bonding properly. On a surface this size — 30 squares of commercial flat roofing — that prep work isn’t a minor step. It determines whether the finished system performs for a decade or starts failing within a couple of seasons.
Proper adhesion on a silicone coating job depends entirely on what happens before the first bucket is opened. Skipping or rushing the prep phase is one of the most common reasons commercial flat roof coatings fail prematurely, and it’s a shortcut CPM doesn’t take.
Box Gutter Repair
With the surface cleaned, the crew turned to the 20 feet of box gutter repair. Box gutters in older commercial buildings are often lined with metal that has corroded, separated at seams, or developed holes that allow water to migrate into the wall assembly below. Left unaddressed, a failing box gutter can cause far more interior damage than a leaking roof membrane.
The repair process involved cleaning out the existing gutter channel, addressing the compromised sections, and restoring the gutter’s ability to carry water away from the building. Completing the gutter work before the coating application ensured that the finished system would function as a unified waterproofing solution rather than a surface fix over a structural problem.
Henry Commercial Silicone Coating
For the roof membrane itself, CPM applied Henry commercial silicone coating across all 30 squares of the flat roof surface. Henry’s silicone product line is a well-established choice for commercial flat roof restoration because it bonds directly to the existing substrate, remains permanently flexible through temperature swings, and maintains its waterproofing properties even in areas where water ponds temporarily after heavy rain.
Silicone doesn’t chalk, crack, or harden over time the way acrylic coatings can. Once cured, it forms a seamless, self-flashing membrane that encapsulates penetrations, drains, and parapet transitions as part of a single continuous system. All pipe penetrations and the area around the existing vent stacks were coated and detailed to ensure there were no weak points in the finished surface.
Solar Ventilation Fan Installation
The original reason the owner called — the solar ventilation fan — was the final piece of the project. Installed directly into the newly coated roof surface and flashed into the silicone system, the solar-powered unit draws heat and moisture out of the 130-year-old attic space without requiring any electrical connection or ongoing utility cost.
Older commercial buildings often have attic assemblies that were never designed with modern ventilation standards in mind. Heat and humidity trapped in those spaces accelerate deterioration of structural members, insulation, and the roof deck itself. A properly sized solar fan running during daylight hours significantly reduces that thermal load and extends the life of everything underneath the roof.
Penetration Detailing and Parapet Work
A flat roof coating is only as good as its weakest detail. Around every penetration — pipe stacks, existing vent collars, the new solar fan base — the Henry silicone was carefully applied in multiple passes to build up thickness and ensure a watertight seal. The parapet walls and interior roof edges were treated with the same attention, extending the coating up and over surfaces where water tends to collect.
This kind of detailing work is invisible once the job is complete, but it’s exactly where flat roof systems fail if the installer cuts corners. On a third-story roof with no easy drainage path in the event of a leak, getting every penetration right isn’t optional.
A 10-Year Warranty on a 130-Year-Old Building
When the project was complete, the building owner walked away with a 10-year warranty on the silicone coating system, repaired box gutters, and a solar ventilation fan running quietly overhead without adding a dollar to his electric bill. For a structure that had been standing for well over a century, that kind of modern protection — delivered without tearing off and replacing the existing roof — represents exceptional value.
The scope grew from a single fan installation to a complete flat roof restoration, but the price point of a coating system versus full replacement made the expanded scope an easy decision. The owner got everything fixed in one visit rather than addressing each issue individually over multiple seasons.
CPM ROOF | Commercial Flat Roof Coating & Repair | Miamisburg & Franklin, OH
CPM ROOF handles commercial flat roof coating, box gutter repair, and ventilation upgrades across the greater Dayton region. Whether your building needs a full silicone restoration or targeted repairs that extend the life of an existing system, the team at CPM delivers solutions built to last. Call (937) 860-2925 to schedule a commercial roof assessment today.