Sheffield Metals Coasteel™: Corrosion-Resistant Metal Roofing for the Coast
Coasteel™ is an aluminum alternative for coastal projects that delivers corrosion resistance and wind performance at a lower cost, for projects between 300–1,500 feet of breaking surf.
Closing the Gap on Coastal Metal Roofs
When it comes to coastal metal roofing projects, contractors face a challenge: delivering on wind performance requirements, defending against saltwater corrosion, and trying to retain profits while buying high-priced aluminum. Coasteel™ offers an ideal solution:
- Corrosion-resistant zinc-aluminum-magnesium substrate
- Wind uplift performance that .032 aluminum can’t match
- Less expensive than both .032 and .040 aluminum
- Premium PVDF paint system
- 20-year substrate warranty and 40-year paint warranty up to 300 feet of breaking surf
How Coasteel™ Compares
| Feature | Coasteel™ (ZAM) | Armored Coast (ZAM) | Coastalume™ | .032 Aluminum | .040 Aluminum | Galvalume |
|---|---|---|---|---|---|---|
| Coastal Suitability (300–1,500 ft) | ✔ Yes | ✔ Yes | ✔ Yes | ▲ Limited (wind) | ✔ Yes | ✘ No |
| Wind Uplift Performance | High | High | High | Low | High | High |
| Relative Cost | $$ | $$ | $ | $$$ | $$$$ | $ |
| Gauge Standard | Minimum | Nominal | Varies | Standard | Standard | Varies |
| Substrate Warranty | 20 Years | 20 Yr 6 Mo | 25 Years | Varies | Varies | Not Coastal Rated |
| Paint / Finish Warranty | 40 Years | 40 Years | 50 Years | Varies | Varies | Not Coastal Rated |
| Coating Technology | Zn-Al-Mg | Zn-Al-Mg | Galvalume + Tedlar® PVF | None (solid Al) | None (solid Al) | 55% Al-Zn |
| Lifespan Positioning | 20-Year Warranted Protection | 20-Year Warranted Protection | 25-Year Warranted Protection | 60-Year Solution | 60-Year Solution | <10 Yr (Coastal) |
| Maintenance Required | Standard | Standard | None (no rinse) | Minimal | Minimal | Standard |
Coasteel™ is engineered for projects 300–1,500 ft from breaking surf. For structures within 300 ft, aluminum is required.
Why Contractors Choose Coasteel™
Corrosion Resistance
Coasteel’s ZAM substrate combines zinc, aluminum, and magnesium to improve corrosion resistance in harsh environments. Its magnesium content helps protect exposed steel areas, which can improve performance in coastal conditions where standard steel substrates are more vulnerable.
Wind Performance
Meets wind uplift requirements where .032 aluminum falls short. Coasteel uses 24-gauge steel to meet modern standing seam metal roofing systems, with a wide variety of testing and engineering availability.
Cost Savings
Coasteel offers a cost-effective option compared to .040 aluminum., allowing you to cut material costs and retain profits.
Built to Last on the Coast
20 yr.
Substrate Warranty*
40 yr.
Paint Warranty*
50+
Colors*
Warranty Coverage*
- Project must be between 300-1500 feet from the coast
- Does not cover exposed fastener systems
- Substrate and paint warranties
Technical Specs
- ZAM (zinc-aluminum-magnesium) alloy coated steel
- 24-gauge steel with available testing and engineering
- Premium PVDF paint system for chalk and fade resistance
*Warranty terms are subject to proper installation and application guidelines. Contact Sheffield Metals for full warranty documentation and coverage details.
*Coasteel currently stocked in five core colors. Other standard colors can be painted with minimums and extended lead times.
*
Ideal Applications
Coastal Residential
Single-family and multi-unit homes in the 300–1,500 feet coastal zone. Wind uplift performance that .032 aluminum can’t match, with corrossion protection Galvalume lacks.
Wood-Look Metal Wall Siding
Coasteel is available in wood-look siding, which is often used as a durable, premium siding that captures the classic look of real wood without any of the drawbacks.
Retrofit / Re-roof
Replacing failed Galvalume roofs in coastal zones. Coasteel provides long-term coastal protection that standard Galvalume couldn’t deliver, without the premium cost of aluminum.
Trusted by Coastal Roofing Professionals
“Green Knight® Metal Roofing has worked with Sheffield Metals for many years. Our assessment is that Sheffield is not only a supplier, they are a partner, integral to the success of our company. I do not believe you could find a better partner for your business anywhere.”
Green Knight Metal Roofing
“We have had an excellent partnership with Sheffield for over the past 15 years. The staff really values our business and always goes the extra step in helping us grow our business.”
ABC Supply
“It’s more of a relationship than a sale. You can find a sale anywhere you want. You can’t find the service and the personalities and the people that you can at Sheffield Metals.”
OH! Metals
“As a contractor, we’ve had an excellent experience working with Sheffield metals. Their customer service team is responsive and knowledgeable, their product quality is consistent and reliable, and we trust them as a partner who stands behind their material. Sheffield has become a manufacturer we can confidently recommend and we continue to rely on for our projects.”
South Texas Metal Roofing
Get the Full Coasteel™ Spec Sheet
Everything your team needs to spec, bid, and install — product data, warranty terms, gauge specs, color options, and installation guidelines in one document.
Available Colors
Available in 40″ master coils and 4’x10′ flat sheets
Regal White
Dove Gray
Matte Black
Silver Metallic
Dark Bronze
Also Available in All 24-Gauge Colors
*May have extended lead times. Non-inventory colors require 5,000 lbs. minimum and are subject to custom fees.
Coasteel™ Also Available in Wood-Look Colors: Sheffield Metals WoodCraft®
Coasteel is the substrate used for Sheffield Metals WoodCraft, a collection of 24-gauge, PVDF wood-look colors featuring:
- Rosewood
- Golden Oak
- Light Walnut
- Warm Gray
Frequently Asked Questions
What is a ZAM coating?
ZAM is a hot dip coated steel made with Zinc, Aluminum, and Magnesium, produced by Wheeling-Nippon Steel. Basically, it’s a steel sheet with a unique metallic coating that provides exceptional corrosion resistance.
Where can Coasteel be installed?
Coasteel can be installed on coastal projects 300–1,500 ft from breaking surf. Whether it’s the right choice for you will depend on three key aspects of your project: proximity from the coast, wind performance requirements, and budget constraints.
How does Coasteel compare to aluminum roofing?
Coasteel can be a strong alternative for projects that need better coastal protection than standard steel, but do not require aluminum for extreme exposure conditions. Coasteel should not be treated as a universal replacement for aluminum. Instead, it’s an economical option for specific projects.
What colors does Coasteel come in?
Coasteel is available in Regal White, Matte Black, Dark Bronze, Dove Gray, and Silver Metallic. Coasteel is also available in all Sheffield Metals 24-gauge colors. These may have extended lead times, and non-inventory colors require 5,000 lbs. minimum and are subject to custom fees.
What does the warranty cover?
The Coasteel warranty comes with a 20-year substrate and a 40-year paint warranty. The warranty DOES NOT cover projects within 300 feet from the coast, or exposed fastener metal roofing systems. Read the warranty carefully to ensure that any exclusions do not apply to your project.
Is Coasteel available in my area?
Contact your local Sheffield Metals branch to see if Coasteel is available.
What do I do if I need to make a warranty claim?
Be sure to contact the manufacturer of your roofing system. If you need to make a warranty claim on a Sheffield Metals roofing system, contact us directly to start the warranty claim process.
Our first steps will be to track down and identify original warranty documents, find specific project information and product records, and collect and analyze information, photos, and other evidence from the property owner. We’ll review the sample products kept by suppliers for the project, and if an issue is detected, we’ll send a representative to the location to investigate. From there, we’ll work together to come to a resolution on the claim.
Get Started with Coasteel™
Request pricing, samples, or connect with a Coasteel specialist.