Common Mistakes Property Owners Make When Coating Their Commercial Roof (And How to Avoid Them)
A quality commercial roof coating can protect a building for decades, reduce cooling costs, and prevent leaks without the expense of a full replacement. But coatings only perform as intended when they’re applied correctly. Many roof coating failures come down to a few avoidable errors during preparation or installation. Below are some of the most common commercial roof coating mistakes and how to prevent them—based on best practices from GAF’s silicone roof coating systems and professional contractor experience.
1. Coating Over a Damaged or Wet Surface
A roof coating is not a repair for existing damage. Applying silicone over a wet or deteriorated substrate traps moisture and causes blisters or adhesion failure later on. Once moisture is sealed in, the coating can separate from the roof membrane, leading to early leaks and warranty issues.
How to avoid it: Inspect and repair the roof before coating. A moisture scan or core sample can confirm the surface is dry and stable. Skipping this step is one of the fastest ways to shorten a coating’s lifespan.
2. Inadequate Cleaning and Surface Preparation
Silicone roof coatings need a clean, properly primed surface to bond effectively. Residue, dust, or oil can prevent adhesion, causing the coating to peel within a few seasons.
How to avoid it: Follow the manufacturer’s cleaning and priming process. GAF’s system specifications require power washing with approved cleaners and primers to ensure proper bonding. Quality prep work often takes longer than the coating itself—but it’s what guarantees performance.
3. Overlooking Drainage or Ponding Water
Even high-performance silicones can degrade faster when ponding water isn’t addressed. Standing water puts extra stress on seams and flashing, and may reduce reflectivity or adhesion over time.
How to avoid it: Before applying a coating, check that the roof drains properly and correct any slope or drainage issues. Coatings work best on roofs that shed water evenly.
4. Hiring the Wrong Contractor
Roof coating systems require specific product knowledge, equipment, and training. An inexperienced contractor might cut corners on prep or apply material at the wrong thickness, which can void the manufacturer’s warranty.
How to avoid it: Work with a contractor certified by the coating manufacturer. GAF’s CoatingsPro+ program, for example, ensures installers are trained on the correct application techniques and inspection standards needed for a full system warranty.
5. Skipping Ongoing Maintenance
Even a properly installed coating needs periodic care. Debris, clogged drains, or small punctures can shorten the roof’s life if ignored.
How to avoid it: Schedule routine inspections once or twice a year, and after major weather events. Minor touch-ups or cleaning can extend the coating’s performance for the full warranty term.
Why Expertise Matters
Silicone roof coatings—like the GAF Silicone Roof Coating System—are proven for UV resistance, energy efficiency, and long-term protection. But their success depends entirely on correct application and follow-through. Choosing a contractor who understands the manufacturer’s system and warranty process ensures the roof will perform as designed.
RiverLand Roofing is a GAF CoatingsPro+ certified contractor authorized to install GAF silicone systems with up to a 20-year No Dollar Limit (NDL) warranty. Our approach emphasizes inspection, preparation, and quality control to meet GAF’s standards—not just for compliance, but for results that last.
The Bottom Line
Most silicone roof coating errors stem from rushing the job or skipping key steps. Careful prep, attention to drainage, and a qualified installation team are what make a coating system reliable. Property owners who take the time to vet their contractor and follow manufacturer guidelines will avoid the most common pitfalls and gain the full value of a commercial roof coating system.