Best Coatings for Old Metal Roofs
Old metal roofs can leak, corrode, and trap heat. The right coating protects metal surfaces, extends life, and lowers cooling costs. This guide reviews five top coatings that perform well on aging roofs, focusing on durability, ease of application, and value. You’ll find options with high reflectivity, strong elasticity, and reliable weatherproofing to fit different climates and budgets.
Summary Of Chosen Products
| Product | Brand | Key Benefit |
|---|---|---|
| Elastomeric Roof Coating 710 White | Rust-Oleum | High reflectivity; fast rain resistance |
| 350 Fibered Black Roof Coating | Rust-Oleum | Premium water and weather proofing; low-temp application |
| Maximum Stretch Roof Coating MSS1 | AMES | 650% elongation; 88% reflectivity; adheres to metal |
| Rubberized SBS Roof Coating 6080 | Gardner-Gibson | Flexible, waterproof seal |
| MetalSafe Sealant | Liquid Rubber | Ultrahigh corrosion protection; UV stable |
Rust-Oleum Elastomeric Roof Coating 710 White
Rust-Oleum Elastomeric Roof Coating in 710 White creates a flexible, seamless membrane that helps aging metal roofs endure weather and temperature swings. The coating emphasizes high reflectivity with 84% initial and 74% weathered reflectivity, contributing to cooler roof surfaces under sun exposure and steadier performance over time. The white finish further reduces heat absorption, supporting lower cooling loads in sunny regions. It is designed to bridge minor surface irregularities on metal roofs while forming a durable barrier against rain and wind.
According to its specifications, this coating achieves rain resistance within about six hours, offering practical protection during shifting weather. The combination of reflectivity, weather resistance, and quick rain protection makes it a strong option for homeowners seeking a long-lasting, low-maintenance solution for older metal roofs. The product is sold in large quantities for substantial roof areas, helping minimize the frequency of reapplications.
350 Fibered Black Roof Coating
Rust-Oleum 350 Fibered Black Roof Coating is formulated as a premium water proofer and weather proofer for smooth asphalt built-up and modified bitumen roofing. While it targets asphalt-based substrates, its coating properties can still benefit aging metal roofs facing moisture intrusion and UV exposure when properly prepared. The product is designed to revitalize older roofs and supports low-temperature application, making it suitable for cooler climates or late-season maintenance. Its fibered composition helps reinforce the coating’s durability across long-term exposure to the elements.
For older roofs where a dark, opaque finish is acceptable, this coating provides robust weatherproofing with practical application in cooler conditions. The low-temperature capability helps crews complete jobs when temperatures are not ideal, reducing the risk of improper curing. Preparation remains essential: clean the surface, remove loose rust, and ensure a solid substrate prior to coating.
AMES Maximum Stretch Roof Coating MSS1
AMES Maximum-Stretch is a white, elastomeric, acrylic, rubberized roof coating with exceptional elongation—up to about 650%—to resist cracking and peeling. The bright white finish features around 88% light reflectivity, reducing surface temperatures and cooling costs in hot climates. This coating adheres well to metal roofing and is versatile enough for tar and rolled roofs as well. A distinctive feature is its capacity to expand and contract with roof movements, a valuable attribute for aging metal roofs that experience expansion and contraction with temperature changes.
Applied by brush, roller, or spray, the coating forms a durable shield that resists weathering while maintaining flexibility. The high elongation helps bridge existing cracks and minor rust-induced gaps, offering a protective layer that stands up to UV rays and moisture exposure. Maintenance considerations include ensuring a clean, dry surface prior to application and inspecting recoat intervals based on climate and roof condition.
Gardner-Gibson Rubberized SBS Roof Coating 6080
Gardner-Gibson 9/30/6080 Rubberized SBS Roof Coating is a 4.75 gallon option that blends rubber and reinforcing fibers to deliver a strong, flexible, waterproof seal. The SBS (styrene-butadiene-styrene) formulation enhances adhesion and resilience on rough or aging surfaces, making it well-suited for old metal roofs that require reliable sealing against leaks. The product’s rubberized composition helps accommodate expansion and contraction while maintaining a robust moisture barrier, preserving roof integrity over time.
Preparation remains key: remove loose rust and debris, ensure the substrate is clean and dry, and apply as directed to achieve the best bond. This coating is particularly effective where metal roofs show cracking or surface irregularities, offering a durable layer that resists weathering and maintains elasticity under temperature shifts.
Liquid Rubber MetalSafe Sealant
Liquid Rubber MetalSafe Sealant is designed for metal roof waterproofing and corrosion protection, with 5 gallons of black coating for large surfaces. It emphasizes ultrahigh corrosion protection and UV stability, making it a practical choice for metal roofs exposed to harsh sunlight and moisture. The formula is easy to apply with a brush or roller and can be sprayed with a heavy-duty airless sprayer for larger jobs. It’s formulated to adhere to metal surfaces and withstand outdoor conditions while delivering a durable, protective membrane.
The product notes that it can be applied over lightly rusted areas, which can be advantageous for aging roofs with surface oxidation. As a sealant rather than a pure elastomeric coating, it emphasizes long-term protection against corrosion and water intrusion, complementing other coatings when metal integrity is a primary concern.
Buying Guide
Choosing the right coating for an old metal roof involves evaluating substrate condition, climate, and maintenance goals. The following factors help compare options and select the best fit:
- Metal compatibility and crack bridging: For rusted or cracked areas, look for high elasticity (elongation) and strong adhesion. Products with rubberized or SBS formulations tend to perform well on metal substrates that move with temperature.
- Reflectivity and thermal management: Lighter colors like white or light gray reduce heat absorption. If cooling costs are a priority, prioritize coatings that advertise high reflectivity and durable UV resistance.
- Elasticity and durability: Coatings with long elongation (hundreds of percent) better resist cracking as roofs expand and contract. This is especially important for aging roofs with prior damage.
- Application conditions: Some coatings are optimized for low-temperature or variable humidity, which broadens the window for maintenance during shoulder seasons or damp climates.
- UV stability and weatherproofing: UV-stable formulas maintain performance over years of sun exposure. Look for membranes that resist wind-driven rain and hail impact.
- Coverage and recoat intervals: Larger containers reduce trips to the store, but ensure the product’s coverage per gallon matches roof size. Plan for maintenance cycles that align with climate and wear patterns.
- Ease of application: Brush, roller, and spray methods each have pros and cons. For large roofs, spray applications can save time, but proper ventilation and safety gear are essential.
- Safety and VOCs: Check for low-VOC formulations if indoor air quality or enclosed spaces are considerations. Always follow manufacturer safety data and cure times.
- Cost vs value: Compare upfront cost with expected lifespan, required coats, and potential energy savings. The least expensive option isn’t always the best long-term value on an aging roof.
- Maintenance and recoat: Some coatings require annual or multi-year recoat cycles, while others offer longer protection. Plan for inspections after severe weather to determine if touch-ups are needed.
When evaluating specific products, align their strengths with the roof’s needs. For a metal roof with surface imperfections and heat concerns, a high-reflectivity elastomeric or a white acrylic coating often provides a balance of durability, energy savings, and ease of application. If corrosion or rust is a dominant issue, choose a coating with strong moisture barriers and compatibility with metal substrates. For roofs with larger movement or existing cracks, a highly elastic product or a rubberized SBS coating can offer superior crack-bridging performance. Always follow surface preparation guidelines to maximize adhesion and longevity.