Guides and insights on commercial flat roof restoration, silicone roof coatings, and roof cost decisions for building owners and facility managers.
ASTM D6694 is the only industry standard for silicone roof coatings. Here’s what it tests — tensile, elongation, tear, solids, permeance — the minimums a product must hit, and how to use it to compare coating bids.
Solids by volume is the share of every gallon of roof coating that stays on your roof after it cures. Because warranties are tied to dry mil thickness, a 96% solids silicone and an 80% solids product need very different gallon counts for the same 20-year term. Here is the two-minute math for comparing coating quotes.
Most commercial roofs get sprayed with silicone coating because it’s faster and lays a more uniform film — but spray isn’t the default for every job. Wind above about 15 mph, tight urban sites, occupied buildings with sensitive HVAC intakes, small or heavily detailed roofs, and standing-seam metal with deep ribs all push a job toward roller and brush instead. A rolled roof isn’t a lower-quality roof: roll and spray silicone systems meet the same ASTM standards and the same mil-thickness-to-warranty-term math. Here’s how contractors actually decide, and what to ask before the crew shows up.
Silicone is a moisture-cured coating, which makes it forgiving of humidity and ponding on a finished roof and completely unforgiving of a hose, pump or pail that has water or the wrong oil in it. A hose that last carried a water-based product cures silicone inside the line. The wrong pump lubricant shows up on your roof as fish eyes. An undersized rig cannot hold 5,000-7,000 psi, and uneven film thickness is a warranty problem in cosmetic disguise. Pails stored outside 50-90 degrees, frozen, or past their 12-24 month shelf life are suspect. Here are the five equipment and material checks any commercial building owner can make on day one.
A brand-new white silicone roof that turns tan, amber or brown within weeks is almost always showing asphalt bleed-through — oils migrating up out of the modified bitumen or built-up roof underneath and staining the coating from below. It does not damage the silicone and it does not affect the waterproofing or the warranty. What it does cost you is reflectivity, and therefore part of the cooling savings the coating was supposed to deliver. Here is why it happens, why a bleed-block primer prevents it for the price of one extra material pass, and what your options are if the roof has already changed color.
Fish eyes, pinholes and craters on a new silicone roof coating are cosmetic workmanship defects — contamination, trapped air or early rain — and a compatible silicone spot coat fixes them in minutes. Blisters are different: they mean moisture was trapped under the coating, and a pattern of them over an unscanned roof can be a warranty denial. Here is how to tell the four apart on a walk-through, how each one is repaired (at the contractor’s cost), and why a job that starts with a moisture scan rarely produces any of them.
Silicone roof coating overspray is real: airless spray rigs atomize the material, wind carries it, and cured silicone does not wash off a car, a window or a rooftop condenser. It is also almost entirely preventable. Here is what a professional crew does before the first pass — wind limits, masking, parking control, rolling instead of spraying near edges and intakes — what happens if something does get hit, and the three things to put in the contract before a coating job starts on an occupied building.
A silicone roof coating that is peeling, sheeting off, or lifting at the seams three years in almost never failed because silicone was the wrong product — it failed because the surface underneath it was not prepared. The good news for building owners: silicone bonds to cured silicone without primer, so a sound but poorly-detailed coating can often be washed, tested and topcoated for $1-2 per square foot instead of stripped. Here is the adhesion test that decides it, what a legitimate contractor will not promise you, and who holds the warranty afterward.
A silicone roof coating adds essentially zero R-value — but it also sidesteps the energy-code rule that forces a full roof replacement to bring insulation up to R-30. On an older commercial roof in PA, NJ, DE, MD, OH or WV, that can mean $60,000–120,000 in insulation and detailing that never shows up on a restoration quote. Here’s what a coating does and doesn’t do for energy, why it’s exempt, and the one real insulation benefit a restoration delivers.
A 20-year silicone warranty running out is not the same thing as a roof running out. Unlike a membrane, a silicone system is designed to be renewed: wash it, topcoat it, and a new warranty term starts — typically at $1–2 per square foot instead of $10–16 for a tear-off. Here’s what the end-of-term inspection actually checks, what a renewal coat costs, and the conditions where a recoat is the wrong answer.
