Older metal roofs require protective coatings that seal against water intrusion, reflect heat, and extend service life. The following select elastomeric and silicone/bitumen-based coatings offer durability, flexibility, and ease of application for metal roof surfaces. This guide highlights five top products with features that address cracking, rust, UV exposure, and budget considerations.
| Product | Brand | Key Benefit |
|---|---|---|
| Rust-Oleum 710 Elastomeric Roof Coating, 5 Gallon, White | Rust-Oleum | High reflectivity and fast cure with long warranty |
| Gardner Sta-kool Elastomeric Roof Coating, 5 Gallon, White | Gardner | Siliconized white coating designed for RV and metal roofs |
| AMES MSS1 Maximum Stretch Roof Coating, 1 Gallon, White | AMES | Very high elongation for flexible, crack-resistant protection |
| Liquid Rubber Waterproof Sealant – Black, 5 Gallon | Liquid Rubber | Superior flexibility with 950% elongation for movement |
| Rust-Oleum 510 Fibered Aluminum Roof Coating, 5 Gallon | Rust-Oleum | Aluminum roof coating with rust protection and energy savings |
Note: Each product offers distinct advantages—cure time, reflectivity, elongation, and ease of application. Consider your roof’s slope, climate, existing rust, and maintenance plans when choosing the coating that best fits your project.
Rust-Oleum 710 Elastomeric Roof Coating
The Rust-Oleum 710 Elastomeric Roof Coating is a 5-gallon white elastomeric coating designed for metal roofs. It features a 10-year warranty and stands out for its waterproof seal within about six hours after application, which minimizes downtime on busy structures. Its cool roof technology delivers roughly 80% reflectivity, contributing to energy cost savings by reducing interior temperatures. This product is suitable for flat and low-slope metal roofs, providing a durable, flexible membrane that resists cracking and weathering over time. Application can be brush, roller, or spray, with performance improvements noted on surfaces that require protection from moisture and UV exposure.
Key considerations:
– Pros: High reflectivity, fast curing, long warranty, strong water seal
– Cons: White color may show dirt; heavy coverage required for larger roofs
– Best for: Long-term protection on metal roofing with energy-saving goals
Gardner Sta-kool Elastomeric Roof Coating
Gardner Sta-kool Elastomeric Roof Coating White is a 5-gallon siliconized white coating designed for RV roofs and metal surfaces. Sta-kool coatings provide elastic protection that resists cracking and weathering, helping to seal joints and seams on older metal roofs. Siliconeized formulations often offer good UV resistance and durability in varying temperatures, which is advantageous for roofs exposed to sun and rain. Application methods include brushing or rolling, with attention to proper surface cleaning and priming if needed on heavily oxidized metal.
Key considerations:
– Pros: Good elasticity, white finish helps with heat reduction, designed for RV and metal roofs
– Cons: May require multiple coats for full cure on rough surfaces
– Best for: Roofs needing flexible sealing with UV resistance
AMES MSS1 Maximum Stretch Roof Coating
AMES MSS1 Maximum Stretch Roof Coating is a white, elastomeric acrylic coating with 650% elongation. This high elasticity helps resist cracking and peeling on aging metal roofs, especially under temperature swings. The bright white finish provides high reflectivity, contributing to cooler roof surfaces and potential energy savings. The coating adheres to metal roofs, tar, rolled roofs, and other surfaces, making it versatile for various roof maintenance tasks. It can be brushed, rolled, or sprayed on, supporting different project sizes and equipment availability.
Key considerations:
– Pros: Very high elongation, good reflectivity, versatile adhesion
– Cons: White finish may require periodic cleaning to maintain appearance
– Best for: Roofs with movement and prior cracking risks
Liquid Rubber Waterproof Sealant – Black
Liquid Rubber Waterproof Sealant in black is a 5-gallon solution designed as a durable waterproof membrane for flat and low-slope roofs, metal roofs, foundations, and gutters. This product emphasizes superior flexibility with over 950% elongation to accommodate building movement and temperature changes, reducing the risk of cracking. It can be brushed, rolled, or sprayed for easy application and aims to deliver long-lasting protection against water infiltration. Coverage varies by surface: around 15 sq ft per gallon on flat roofs (with multiple coats) and up to 30 sq ft per gallon on vertical surfaces like foundations.
Key considerations:
– Pros: Exceptional elongation, strong waterproofing, versatile usage
– Cons: Requires multiple coats for full membrane on flat roofs
– Best for: Roofs needing flexible, durable protection against movement and UV exposure
Rust-Oleum 510 Fibered Aluminum Roof Coating
Rust-Oleum 510 Fibered Aluminum Roof Coating is a 5-gallon option featuring a fibered aluminum formulation. It provides rust protection for metal roofs and offers Cool Roof Technology with approximately 53% reflectivity, contributing to energy savings by reducing heat buildup. The coating is designed to form a durable, protective layer that resists weathering and extends roof life. Its aluminum content helps reflect solar radiation and can help moderate surface temperatures on sunny days. Application methods include brush, roller, or spray, depending on project scale and equipment availability.
Key considerations:
– Pros: Rust protection, energy-saving reflectivity, durable aluminum finish
– Cons: Aluminum color may show wear or discoloration over time
– Best for: Metal roofs needing rust protection with energy efficiency goals
Buying Guide: Key Purchase Considerations
When selecting a coating for an old metal roof, consider these factors to ensure a durable, long-lasting result:
- Elongation and flexibility: Higher elongation reduces cracking on aging metal roofs. Look for products with 650% or higher elongation if you expect movement or temperature swings.
- Reflectivity and energy savings: White or light-colored coatings reflect more heat, lowering roof surface temperatures and indoor cooling loads.
- Adhesion to metal: Check compatibility with rusted, corroded, or previously coated metal surfaces. Some formulations are specifically designed for metal roofs.
- Weather and cure times: Consider climate and project timing. Fast-curing products minimize downtime but may require more coats for full protection.
- UV resistance and durability: UV stability helps prevent chalking and degradation over time, especially in sunny climates.
- Ease of application: Brush, roller, or spray options affect labor and equipment. Larger roofs may benefit from spray-ready formulations.
- Color and appearance: White coatings aid cooling but may require periodic cleaning. Aluminum or darker coatings offer different aesthetics and reflectivity.
- Warranty and coverage: Review product warranties and coverage rates to estimate total material needs and replacement costs.
Bottom line: For an old metal roof, a coating with high elasticity, good UV resistance, and strong water sealing capabilities tends to perform best over time. Align product choice with roof condition, climate, and maintenance plans to maximize protection and energy efficiency.