When it comes to protecting a roof, homeowners and building owners are always searching for solutions that are both effective and affordable. One option that often shows up on the shelves at big-box retailers like Home Depot and Lowe’s is aluminum roof coating. At first glance, it might seem like a simple and cost-effective way to extend the life of a roof—but looks can be deceiving.
The reality is that aluminum coatings are often marketed by unqualified “contractors” or handymen who claim the product will provide a long-lasting, 7 year warrantied fix. In truth, the only warranty attached to these coatings is a limited manufacturer’s warranty—and the fine print states that if the roof surface is not properly cleaned and prepared before application, that warranty becomes void.
Even when applied correctly, aluminum coatings don’t hold up well over time. As you can see in the picture above, within just 2–5 years, they begin to wear thin, flake, and peel away. Once this happens, you’re left with a roof surface that cannot be effectively repaired or re-roofed, since new materials will not adhere properly to the remnants of the coating.
In other words, what seemed like a quick fix can actually leave you with fewer options and higher costs down the line. Before rolling on a coating, it pays to do your homework—and to invest in a solution that truly protects your roof for the long term.
Cons of Using Aluminum Roof Coatings
- Inability to Adhere: One of the main issues with aluminum coatings is their inability to bond with adhesives or water-based coatings, which can be problematic if you decide to re-roof or apply a longer-lasting silicone or acrylic product in the future. While a solvent-based primer can improve adhesion, it will not be a reliable solution for re-roofing.
- Beware of Rain: Aluminum coatings are not effective in protecting against water, except for hairline cracks. This means that if your roof has any significant leaks, an aluminum coating will not provide watertight protection. Only silicone can provide a truely watertight coating that will fill up cracks and gaps.
- Unable to Fluctuate: Another major issue with aluminum roof coatings is that they do not expand and contract with changing temperatures. This can cause the coating to develop bubbles, cracks, and gaps, leading to potential water damage and other issues.
- Lackluster Warranties: While warranty options may vary depending on the manufacturer, aluminum coating products typically offer a limited manufacturer warranty of only one to seven years. You almost never see the roofers that offer the alumimun coating offer a real workmanship warranty. This means that if any issues arise with your roof, you may be responsible for costly repairs or replacements.
- Subpar Reflectivity: Despite claims of lowering roof temperatures and reflecting ultraviolet rays, aluminum coatings are not as efficient in solar reflectance and thermal emissivity as silicone or acrylic coatings. According to the Cool Roof Rating Council, an organization that evaluates solar reflectance and thermal emittance, aluminum roof coatings are 20% less efficient in these areas compared to silicone or acrylic coatings. Additionally, aluminum coatings can lose up to 50% of their efficiency within just three years, resulting in higher energy costs over time.
- Difficult to Clean: Cleaning is an essential part of roof maintenance, but it can be tricky with an aluminum coating. During the cleaning process, aluminum flakes can slough off, exposing the substrate below and releasing aluminum particles into the environment. This can be hazardous to the health of those in the surrounding area.
- High VOC Content: Aluminum coatings are solvent-based, which means they can emit noxious odors during application. This can be a concern for building occupants and may require special precautions during installation.
- Frequent Recoating Needed: Finally, aluminum roof coatings typically have a lifespan of only three to four years, meaning you'll need to re-coat often to maintain protection. This can be a time-consuming and costly process, especially for larger commercial roofs. A silicone roof coating can last 20+ years.
Better Alternatives to Aluminum Coatings
While aluminum roof coatings may seem like a good option due to their low initial cost, there are better alternatives available that can provide superior protection and longevity for your roof. Some of these alternatives include:
- Silicone Coatings: Silicone roof restoration involves applying a high-performance high solids silicone coating over an existing roof membrane—such as EPDM, TPO, Modified Bitumen, PVC, or metal—to reinforce its weatherproofing capabilities. This process offers numerous benefits, including improved water resistance (completely waterproof in areas of ponding), enhanced UV protection, and potential energy savings due to increased solar reflectivity (93%). By avoiding a complete roof tear-off, silicone roof restoration can also save time and labor costs. You can get a warranty for 5, 10, 15, or 20 years.
- Acrylic Coatings: Acrylic coatings are water-based and can bond to a wider range of surfaces, making them more versatile than aluminum coatings. They also have better reflectivity and emissivity, making them more efficient at reducing roof temperatures and energy costs. The main drawback to Acrylic coatings is that it cannot withstand ponding water like silicone can. Acrylic coatings can last up to 10 years or more with proper maintenance.
- Polyurethane Coatings: Polyurethane coatings are solvent-based but have lower VOC emissions than aluminum coatings. They are also durable and resistant to wear and tear, making them a good choice for high-traffic roofs.
Before making a decision on which type of roof coating to use, it's important to consult with a roofing professional who can evaluate your specific needs and recommend the best solution for your property.
Conclusion
While aluminum roof coatings may seem like an attractive option for protecting your roof, there are several drawbacks to consider before making a decision. These coatings may not be the best choice for those looking for a long-term, effective solution. Instead, it may be better to explore alternative options such as silicone, acrylic, or polyurethane coatings. By working with a roofing professional and conducting thorough research, you can ensure that you make an informed decision and choose the best product for your property.
Trust GoTech Roofing in Washington DC, Virginia, and Maryland
Founded by Julian Stevens over 15 years ago, GoTech Roofing has established itself as the number 1 provider of roof coating services. We provide roof repair and roof replacement services with a real focus on customer satisfaction. We are a Washington DC, Virginia, and Maryland Class A Contractor and fully insured with Workman's Compensation and Liability Insurance. GoTech Roofing provides each and every client with an incomparable flat roofing experience through our outstanding customer service and exceptional quality.
If your roof is still structurally sound but has leaks, ponding water, or worn seams, it may be a great candidate for silicone roof restoration. Roofs with aged but intact membranes can often be renewed with a silicone coating system, which stops leaks, extends roof life by 20 years, and avoids the high cost of a full tear-off and replacement. Click the link below to see if you roof is a candidate for for Silicone Roof Restoration.