Silicone Rescue of a 54-Year-Old Metal Roof in Santa Rosa CA

A steel commercial building in Santa Rosa, California, home to a plumbing and heating supplies business, had been protected by the same metal roof since the 1960s. At 54 years old, the 26,000-square-foot roof was leaking, and a full replacement carried an estimated cost in the neighborhood of a quarter of a million dollars. Bay Area contractor Wedge Roofing proposed a different path: restore the existing panels with a fluid-applied silicone system.

The Challenge

Decades of weather had corroded the roof at its most vulnerable points. Panel laps, joints, and fasteners had all deteriorated, and the building’s 24-gauge galvanized steel box gutter was corroded as well. Any restoration would need to address both the field of the roof and that failing gutter, and it had to be done without interrupting the business operating below.

The Coating Solution

Led by project manager Gary Harvey, the Wedge Roofing crew installed new neoprene-gasketed fasteners and lined the box gutter with 60-mil non-reinforced TPO membrane to give the drainage system a fresh waterproof surface. Across the metal panels, the team applied Huntsman Building Solutions Thermo-Sil NP silicone coating in white, building the membrane to 45 dry mils. Number 11 ceramic granules in a Fire White finish were broadcast into the topcoat, adding traction and durability to the reflective surface. The entire restoration was completed in six days.

The Results

The project stopped the leaks, extended the service life of a half-century-old roof, and spared the owner the cost and disruption of tear-off and replacement, along with the landfill waste that would have come with it. The work earned industry recognition as well, winning the 2022 Spray Polyurethane Foam Alliance National Industry Excellence Award in the elastomeric roof coatings category.

Project photos