Ponding water is one of the most common problems we find on flat roofs across this river valley, and silicone coating is the material built specifically to handle it. Where an acrylic coating breaks down under standing water, silicone holds up, which makes it the right call on a specific class of roofs rather than a universal upgrade.
Southern Indiana gets substantial rainfall across spring and summer, and a lot of older flat roofs in this region, particularly on buildings built decades ago near downtown and around the university campuses, were never built with tapered insulation to shed water toward drains. The result is standing water that can sit for days after a storm rather than draining off within hours.
Ponding accelerates membrane aging, breaks down UV-resistant coatings that aren't rated for constant water contact, and adds structural load the building wasn't necessarily designed to carry long-term. Identifying ponding areas is usually the first thing we flag on an inspection of an older roof.
Flat-roofed retail buildings built during a single era of rapid strip-mall construction decades ago share this problem across the board, since the design standards of that period rarely called for the drainage slope building codes require on new construction today.
Silicone coating works well over existing TPO, EPDM, modified bitumen, and metal roofs that are structurally sound but showing UV wear, chalking, or minor ponding damage. It's a restoration option, not a fix for a roof with failed insulation or a compromised deck underneath.
We run a moisture scan before recommending a silicone recoat on any roof, since coating over wet insulation traps the moisture rather than solving anything. A roof with widespread wet insulation needs tear-off and replacement, not a coating, no matter how well the coating itself would otherwise perform.
Metal roofs with surface rust or coating breakdown, but no structural corrosion, are also reasonable silicone candidates, since silicone bonds well to properly primed metal and adds a reflective, weather-resistant surface without the cost of a full panel replacement.
A silicone recoat starts with cleaning the existing membrane surface, since dirt, chalk residue, and biological growth all interfere with adhesion. Damaged seams and flashing get repaired before coating goes down, not covered over. The coating is then applied at a specified mil thickness, often in multiple passes, with extra material at seams, penetrations, and low points where ponding concentrates.
Weather timing matters for application too. Silicone coating needs a dry substrate and a forecast window without rain during cure time, which in a region prone to sudden spring storms means crews watch the forecast closely and sequence sections to match realistic dry windows rather than committing the whole roof at once.
On a silicone coating project we confirm:
A silicone coating adds years of service life to a roof that isn't ready for full replacement, at a fraction of the tear-off and replacement cost. It's a decision we walk through honestly with building owners, since a roof with underlying structural or moisture problems isn't a good coating candidate regardless of what a lower-cost bid promises.
We'll tell a building owner directly when a coating is the wrong answer, even though it's a smaller job than a full replacement, because a coating over the wrong roof just delays a bigger cost down the line.
Most silicone coating systems carry a manufacturer warranty tied to mil thickness actually applied, verified through core samples or wet-mil gauge readings during installation rather than taken on faith after the fact.
We recommend an annual check on a coated roof, focused on seams, flashing transitions, and any new ponding areas that might develop as a building settles or drainage patterns shift over time, since a coating doesn't eliminate the need for ongoing inspection. Catching a thin spot early is a short repair; catching it after a leak develops underneath is a much bigger one.
It doesn't fix drainage slope, but it resists the UV and moisture breakdown that ponding causes to an unprotected membrane, which extends service life significantly.
It depends on mil thickness applied and existing roof condition, which is why we scope the project around your specific roof rather than a generic number.
Most single-ply, mod-bit, and metal roofs are candidates if the substrate is sound and dry. A roof with wet insulation needs replacement, not a coating, no matter how good the coating product itself is.
Generally yes, on a roof that's a legitimate candidate. It's restoration, not a substitute for replacement when the underlying roof is failing.
Always. Coating over wet insulation just seals the moisture in, so a moisture scan comes before any coating recommendation, regardless of how the roof looks from a walk-through alone.