If you manage or own a commercial building, you’ve probably heard the same chorus on roof coatings: “They peel.” “They yellow.” “They blister.” “They trap moisture.” “They’re slippery and hard to maintain.” We agree these problems happen—and they’re frustrating and expensive.
But here’s the truth that rarely gets said out loud: most coating horror stories come from skipping manufacturer specifications, using the wrong chemistry for the roof conditions, installing over hidden moisture, or “value engineering” out key system components (primers, fabric reinforcement, bleed-blockers, walk pads) to win a low-bid quote. The coating system didn’t fail—the process did.
Below, we acknowledge each common complaint and then show exactly how a properly specified and professionally installed system prevents it. This article is written for building owners doing real due diligence, and it’s designed to help you ask the right questions and avoid the avoidable.
Common Complaints (We Agree) — And How Proper Specs Prevent Them
“Coating systems peel up after a few years.”
- Agree. This happens when surfaces aren’t clean/dry, the wrong primer is used, or dew point and cure windows are ignored.
- Do it right: Power-wash and clean to spec, dry to manufacturer moisture limits, then use the correct primer for your roof type (e.g., rust-inhibitive on metal, bleed-block on modified bitumen, specialty primers for TPO/EPDM). Poor surface prep and moisture contamination are top-cited failure causes in industry guidance from contractors and manufacturers alike. See discussions of prep, moisture, and application errors in resources like Kapili Roofing and National Coatings.
“Coating systems turn yellow.”
- Agree. Often caused by asphalt bleed-through on modified bitumen or BUR.
- Do it right: Use a bleed-blocking primer on asphaltic substrates. It prevents staining and preserves reflectivity. When bids cut this step, yellowing is almost guaranteed.
“Coatings encapsulate moisture under the roof.”
- Agree—if you coat over wet insulation or a damp deck.
- Do it right: Perform an infrared moisture scan and targeted core cuts before coating. Replace wet areas first. Stage work to dew-point and temperature windows. Moisture contamination leads to blisters and delamination; this is a known failure mode highlighted by contractors such as Parsons Roofing and Kapili Roofing.
“Acrylic coatings fail with ponding water.”
- Agree. Many acrylics aren’t intended for long-term ponding and can soften or delaminate.
- Do it right: Match chemistry to conditions. On roofs with chronic ponding, silicone or urethane-silicone hybrid systems are preferred. Even acrylic-forward manufacturers caution against acrylics in ponding situations—see American WeatherStar’s note on acrylics and ponding.
“Silicone roofs get dirty and lose reflectivity.”
- Agree. Silicone can pick up airborne dust and look dingy over time.
- Do it right: Plan for periodic cleaning and choose high-solids formulations with better dirt pickup resistance. Despite some dirt accumulation, silicones typically retain reflectivity longer than other chemistries per industry commentary (Progressive Materials). Dirt pickup is aesthetic and manageable with maintenance.
“Silicone is slippery and hard to repair; nothing else sticks to it.”
- Partly true. Silicone can be slick when wet, and future recoats should be silicone unless you abrade/prime for compatibility.
- Do it right: Install walk pads and traction surfacing along service routes. Plan lifecycle recoats with silicone-on-silicone—this is standard practice and straightforward when planned up front (see recoat considerations from Choice Roof Contractor Group).
“Bubbling, blisters, and wrinkles appeared in the coating.”
- Agree. Usually from applying too thick, coating over damp substrates, or skipping seam/penetration reinforcement.
- Do it right: Follow manufacturer wet mils and total film thickness, respect cure/recoat windows, and reinforce seams, penetrations, and transitions with flashing-grade coating plus polyester fabric before field coats. Over/under-application is a documented cause of defects (National Coatings, Rubberized).
“The coating washed off in a rainstorm.”
- Can happen with water-based coatings (e.g., acrylic) if rain hits before cure.
- Do it right: Install with correct weather windows and consider chemistry: silicones moisture-cure and don’t “wash off” like acrylics if rain hits early (Progressive Materials).
“UV destroyed the coating.”
- UV degrades all materials over time.
- Do it right: Use UV-stable topcoats appropriate for your climate; silicones and urethanes are known for UV durability. Schedule inspections and recoat before film erosion reaches below-warranty thickness (A. Fricker Roofing).
“Leaks started at seams, fasteners, and penetrations.”
- Agree—when crews skip fabric and flashing-grade details to save time or cost.
- Do it right: Most systems require a 3-course detail (flashing-grade coating + polyester fabric + coating) at all seams, penetrations, transitions, and terminations prior to field coating. Skipping this step is one of the fastest ways to ensure leaks (Parsons Roofing).
The Real Root Causes (and How to Avoid Them)
- Inexperienced or rushed installers
- Treating coatings like “paint” leads to skipped prep, missed details, and warranty-voiding mistakes. If a bid timeline seems unrealistically fast, ask exactly which prep and detail steps are included.
- Wrong product for the roof conditions
- Acrylic on a ponding roof, no bleed-block on modified bitumen, no rust-inhibitive primer on metal, or no compatible primer on TPO/EPDM—these are specification errors, not product failures. Make sure chemistry matches roof conditions and manufacturer guidance (American WeatherStar).
- Budget-driven scope cuts
- Low bids that eliminate primers, fabric, moisture diagnostics, additional coats, and walk pads often “save” now but cost later. Ask every bidder to list all primers, reinforcements, and total dry film thickness in writing.
What a Properly Executed Coating Project Looks Like
- Diagnostics first
- Infrared moisture scan + targeted core cuts
- Roof survey of seams, penetrations, fasteners, rust, ponding zones, and previous coatings
- Substrate preparation
- Power-wash/clean to spec, repair flashings and seams, tighten/reseal fasteners, rust-treat metal, remove/replace wet insulation, dry to moisture thresholds
- Primers and details (don’t cut these)
- Bleed-block for mod bit/BUR; rust-inhibitive for metal; TPO/EPDM-compatible primers; adhesion tests where required
- 3-course reinforcement at seams, transitions, penetrations, terminations
- Chemistry matched to conditions
- Chronic ponding: silicone or urethane-silicone hybrids
- Positive drainage/sloped metal: silicone or advanced acrylics (with clear understanding of ponding limits)
- Application discipline
- Correct wet mils and total DFT, respect recoat and cure windows, stage work to weather, mix per spec without entraining air
- Traffic and maintenance
- Add walk pads on service routes, schedule semiannual inspections/cleaning to maintain performance and reflectivity
Straight-Answer FAQs
- Are coatings just a band-aid?
- Only if you skip diagnostics and detailing. With moisture remediation, proper primers, reinforcement, and suitable chemistry, coatings are a durable restoration—often with 10–20-year manufacturer warranties.
- Will coatings trap moisture?
- Not if you remove wet insulation first and apply within dew-point windows. Moisture surveys are step one for responsible coating projects.
- Do acrylics always fail?
- No. Acrylics can perform well on roofs with positive drainage (e.g., sloped metal). They’re not the right choice for chronic ponding areas, where silicone or hybrids excel.
- Is silicone impossible to maintain later?
- Plan for silicone-on-silicone recoats and install walk pads. Maintenance is straightforward when you plan the lifecycle up front.
Buyer’s Checklist You Can Use With Any Contractor
Ask every bidder to provide, in writing:
- Infrared moisture report and plan to remove/replace wet insulation
- Exact primers to be used (by substrate) and where
- Fabric-reinforcement plan for seams, penetrations, transitions, terminations
- Coating chemistry, specified wet mils, and total dry film thickness
- Weather/cure plan (dew point, rain windows)
- Walk pad layout and maintenance plan
- Manufacturer warranty type and term (materials-only vs. labor-and-material, inspection requirements)
If any of these items are missing—or offered “only if needed”—you’re likely looking at a scope that invites the very failures people complain about.
Sources and further reading:
- Acrylic and ponding limitations — American WeatherStar
- Causes of coating failures (prep, moisture, UV, application) — Kapili Roofing
- Application issues (thickness, blisters, bubbles) — National Coatings
- Silicone pros/cons and myths — Progressive Materials, Choice Roof Contractor Group, Rugged Coatings
- Common mistakes to avoid (thickness, cure, rain timing) — Rubberized
Contact Brown’s Roofing today for a roof coating estimate!