Silicone coating is the system we reach for most often when a roof has ponding water that isn't going away and a full tear-off isn't yet justified by the roof's overall condition. Unlike most other coating chemistries, silicone tolerates standing water without breaking down, which makes it the right tool for a specific and common problem on Roanoke's older, flatter commercial roofs.
Acrylic and most other coating systems degrade under sustained water contact, which means they're a poor match for roofs with drainage issues that pond water for more than 48 hours after rain. A lot of Roanoke's older flat roofs, particularly built-up and modified bitumen systems installed before current slope-to-drain code requirements, have low spots that pond regularly regardless of how well the rest of the roof drains.
Silicone's chemistry is different. It cures into a coating that stays stable under standing water rather than softening or hydrolyzing, which is why we specify it on roofs where correcting the drainage isn't in the budget this cycle but the roof still needs protection now.
A coating restores a weatherproof surface and adds UV protection to an aging membrane, metal, or built-up roof, but it doesn't fix a structural problem or reverse existing moisture damage in the insulation below. Before recommending a coating, we scan the roof for wet insulation, since coating over trapped moisture just seals the problem in rather than solving it.
On a roof that passes the moisture check, silicone coating restores reflectivity, seals minor surface cracks and seams, and buys years of additional service life at a fraction of tear-off and replacement cost. We treat it as a maintenance and life-extension tool for a roof in decent underlying condition, not a fix for a roof that's already failing structurally.
Silicone coating adhesion depends entirely on surface prep. We pressure wash the existing roof to remove dirt, chalking, and biological growth, then let it dry fully before applying. Skipping or rushing that step is the most common cause of premature coating failure we get called to diagnose on roofs coated by someone else. On metal roofs specifically, we treat rust spots and re-seal seams before coating rather than coating over active corrosion.
Coating thickness matters as much as prep. We apply at the manufacturer's specified wet mil thickness, checking as we go rather than eyeballing coverage, since an under-applied coating looks fine on installation day and fails within a season or two once it's stretched too thin to do its job.
On roofs with active seam or flashing weakness, we embed polyester fabric reinforcement into the coating at those specific locations before applying the field coat. That reinforcement bridges small gaps and adds tensile strength exactly where the roof needs it most, at penetrations, seams, and transitions, rather than relying on coating thickness alone to hold a marginal detail together.
Silicone coatings aren't a one-time fix. UV exposure gradually wears the coating down over roughly ten to fifteen years depending on the roof's exposure, at which point a maintenance recoat restores the protective layer rather than requiring a full reapplication process. We build recoat timing into the maintenance plan we hand off after the initial application so an owner knows what to expect and budget for down the line.
We also track coating thickness at each maintenance visit rather than waiting for visible wear to show up, since a coating that's worn thin in a specific area, usually a spot with heavier foot traffic or steeper sun exposure, needs attention before the rest of the field does. Addressing those localized thin spots during a routine visit is far cheaper than letting them progress into an active leak.
It won't eliminate ponding, since that's a drainage and slope issue, but it protects the roof surface from the degradation that ponding causes to other coating types and most membranes over time. Correcting the underlying drainage is still the long-term fix.
Yes, that's specifically what silicone is formulated for. Other coating chemistries can't tolerate standing water; silicone is one of the few that performs reliably under it.
We check for wet insulation and structural condition first. A dry, structurally sound roof with surface-level wear is a strong coating candidate. A roof with widespread moisture damage needs replacement regardless of what coating is applied on top.
Roughly ten to fifteen years before a maintenance recoat is needed, depending on UV exposure and roof slope. We include recoat timing in the maintenance plan at the time of application.
Yes, after treating any rust spots and resealing failing seams first. Coating over active corrosion just traps the problem under a new surface rather than resolving it.
