Steel roofing accounts for roughly 60% of all metal roofing installed in the United States. It's strong, relatively affordable (compared to aluminum or copper), and available in dozens of profiles and finishes. But Florida is not most of the United States. The combination of salt air, intense UV, hurricane-force winds, and high humidity means that not all steel roofing performs equally here.
This guide covers every type of steel roofing available, how each performs specifically in Pinellas County's environment, and when you should choose steel versus other materials.
Steel Roofing Substrates: Galvalume vs Galvanized
The steel panel itself is just the core. What protects it from corrosion is the coating applied at the mill, and this is where the critical difference lies.
Galvanized Steel
- Coating: Pure zinc applied by hot-dip process
- Protection mechanism: Zinc sacrificially corrodes, protecting the steel underneath
- Lifespan in FL: 20-30 years (less near salt water)
- Cost: Lower than Galvalume
- Best for: Agricultural buildings, carports, temporary structures, inland locations
- Weakness: Zinc coating depletes faster in salt air and high humidity environments
Galvalume Steel (55% Aluminum-Zinc Alloy)
- Coating: 55% aluminum, 43.5% zinc, 1.5% silicon alloy
- Protection mechanism: Aluminum provides barrier protection while zinc provides sacrificial protection at cut edges
- Lifespan in FL: 40-60 years with proper paint system
- Cost: 10-15% more than galvanized
- Best for: Residential and commercial applications where longevity matters
- Standard: ASTM A792 (the industry specification for Galvalume)
For any residential steel roof in Pinellas County, Galvalume is the minimum acceptable substrate. Galvanized-only steel panels are appropriate for agricultural and industrial applications where aesthetics and 50-year lifespan aren't the priority.
Steel Gauge: What the Numbers Mean
| Gauge | Thickness (inches) | Weight (psf) | Wind Resistance | Best Application | Cost Impact |
|---|---|---|---|---|---|
| 29 gauge | 0.0141" | 0.56 | Moderate | Agricultural only | Cheapest |
| 26 gauge | 0.0179" | 0.71 | Good | Residential (minimum) | Base |
| 24 gauge | 0.0239" | 0.95 | Excellent | Residential/commercial standard | +15-20% |
| 22 gauge | 0.0299" | 1.19 | Superior | Commercial, high-wind zones | +30-40% |
For Pinellas County residential applications, 24-gauge Galvalume is the recommended standard. 26-gauge is acceptable for budget-constrained projects but offers less dent resistance and wind uplift capacity. Never install 29-gauge on a home.
Paint Systems: The Real Longevity Factor
The paint system on a steel roof matters more than most homeowners realize. It's the first line of defense against UV degradation, and in Florida, UV is relentless.
Kynar 500 / Hylar 5000 (PVDF)
- The premium standard for residential and architectural metal roofing
- 70% PVDF resin (polyvinylidene fluoride), the same chemistry used on high-rise curtain walls
- Color retention: 30-40 years before noticeable fading (Delta E less than 5)
- Chalk resistance: Excellent (ASTM D4214 rating of 8+ after 20 years)
- Warranty: 35-40 year paint warranty from most manufacturers
- This is what you want on any residential steel roof in Florida.
SMP (Silicone Modified Polyester)
- Mid-tier paint system
- Color retention: 15-25 years in FL conditions
- Chalk resistance: Moderate (will show chalking in 10-15 years in FL sun)
- Warranty: 25-30 year paint warranty
- Cost: 15-20% less than Kynar
- Acceptable for: Commercial/industrial where aesthetics are secondary to function
Polyester
- Economy paint system
- Color retention: 5-10 years in FL (fades significantly)
- Not recommended for residential applications in Florida
- Common on: Agricultural panels, temporary structures
The Salt Air Problem
This is the critical consideration for Pinellas County. We're a peninsula surrounded by water on three sides: the Gulf of Mexico to the west, Tampa Bay to the east, and Boca Ciega Bay running through the middle.
Most steel roofing manufacturers have coastal exclusion zones:
- Within 1,500 feet of salt water: Warranty is typically voided entirely or reduced to material-only (no labor, no consequential damage)
- 1,500-2,500 feet: Warranty may be reduced (shorter term, more exclusions)
- Beyond 2,500 feet: Full warranty typically applies
In Pinellas County, a significant percentage of homes fall within these exclusion zones. Before choosing steel roofing, measure your distance from the nearest salt water body. Use Google Earth's measurement tool for accuracy.
If you're within 1,500 feet of salt water: Consider aluminum standing seam instead. Aluminum does not corrode in salt air, carries full coastal warranties, and costs only 15-25% more than steel. For a waterfront property, the warranty protection alone justifies the premium.
Stone-Coated Steel: The Florida Sweet Spot
Stone-coated steel roofing deserves its own section because it solves several of steel's weaknesses while maintaining its strengths.
How it works: A Galvalume or ZINCALUME steel core is coated with acrylic adhesive, then embedded with crushed natural stone granules, then sealed with an acrylic overglaze. The stone layer provides UV protection, aesthetic variety, and an additional corrosion barrier.
| Brand | Core | Profiles | Warranty | Wind Rating | Cost/sq ft |
|---|---|---|---|---|---|
| DECRA | ZINCALUME | Shake, Shingle, Villa Tile | Lifetime limited transferable | Up to 180 mph | $9-14 |
| Boral | Galvalume | Shake, Shingle, Tile, Slate | 50-year limited | Up to 180 mph | $8-13 |
| Metro | Galvalume | Shake, Shingle, Tile | Lifetime limited | Up to 165 mph | $8-12 |
| Tilcor | ZINCALUME | Shake, Shingle, Bond | 50-year limited | Up to 170 mph | $9-13 |
Why Stone-Coated Works in Florida
- Wind ratings: 165-180 mph tested, exceeding FBC requirements for all of Pinellas County
- Weight: 1.3-1.6 lbs/sq ft (lighter than tile, heavier than panels, no structural reinforcement needed)
- Appearance: Mimics shake, slate, or tile without the weight, fragility, or cost of the real thing
- Hail resistance: Class 4 impact rating (UL 2218), the highest available
- Salt air: Stone coating provides additional corrosion barrier, though coastal exclusions may still apply (check specific manufacturer)
- Insurance: Class 4 impact rating often qualifies for insurance premium discounts
Steel Roofing Costs in Pinellas County
| Type | Cost/sq ft (installed) | 2,000 sq ft Roof | Lifespan in FL |
|---|---|---|---|
| Exposed fastener (R-panel, 26ga) | $4.50-7.00 | $9,000-14,000 | 25-35 years |
| Exposed fastener (corrugated, 24ga) | $5.00-8.00 | $10,000-16,000 | 30-40 years |
| Standing seam steel (24ga, Kynar) | $8.00-14.00 | $16,000-28,000 | 40-60 years |
| Stone-coated steel | $9.00-15.00 | $18,000-30,000 | 40-70 years |
| Standing seam ALUMINUM | $10.00-18.00 | $20,000-36,000 | 50-75 years |
Steel vs Aluminum: The Florida Decision
| Factor | Steel | Aluminum |
|---|---|---|
| Cost | 15-25% less | Higher |
| Salt air corrosion | Vulnerable (coating dependent) | Immune |
| Coastal warranty | Voided or reduced within 1,500 ft | Full warranty |
| Strength/dent resistance | Superior | More susceptible to dents |
| Weight | Heavier | Lighter (0.5-0.7 lbs/sf) |
| Thermal expansion | Less | More (requires proper clip design) |
| Color options | Extensive | Extensive |
The simple rule: If you're more than 2,500 feet from salt water and budget matters, steel with Kynar coating is an excellent choice. If you're within 1,500 feet of salt water, spend the extra for aluminum. The warranty protection alone saves you money in the long run.
Get a Free Metal Roofing Consultation
We install both steel and aluminum metal roofing throughout Pinellas County and can help you determine which material is appropriate for your specific location and budget. Schedule a freeroof inspection and we'll provide a detailed comparison for your property. Use our roof cost calculator for an instant estimate. ServingSt. Petersburg, Clearwater, and all of Pinellas County.