This tool walks you through each specification decision for your metal roof — panel system, gauge, coating, fasteners, underlayment, and more. At the end, you will get a complete specification sheet that you can share with contractors to ensure accurate, comparable quotes. Each choice includes guidance on why it matters. For background on each specification, see our standing seam guide, exposed-fastener guide, or stone-coated steel guide.

Panel System

The panel system is the single biggest cost and performance variable. Each system has a different attachment method, maintenance profile, and price range.

Standing Seam

Concealed fasteners, engineered clips, highest wind resistance. $8-14/sq ft. Recommended for primary residences, coastal homes, and long-term ownership.

Exposed-Fastener

Face-screwed panels, simpler installation, lower cost. $4-8/sq ft. Budget option with a washer replacement cycle at 15-20 years.

Stone-Coated Steel

Traditional tile/shake/shingle appearance with steel substrate. $6-10/sq ft. Good for HOA-restricted neighborhoods.

Substrate Material

The metal beneath the coating. Distance from saltwater drives this choice.

Galvalume Steel (AZ55)

Standard for most Gulf Coast installations. Excellent atmospheric corrosion resistance. Suitable beyond 1,500 feet from saltwater.

Aluminum

Cannot rust. Recommended within 1,500 feet of saltwater. 30-50% more expensive than Galvalume but provides unlimited corrosion life.

Galvanized Steel (G90)

Budget option. Adequate for inland installations but outperformed by Galvalume in atmospheric corrosion. Better cut-edge protection than Galvalume.

Gauge Thickness

Thicker metal resists denting, holds fasteners better, and reduces oil canning. Lower gauge number = thicker metal.

24-Gauge (0.024")

Premium choice. Maximum dent resistance, minimal oil canning, strongest wind performance. 15-20% more than 26-gauge.

26-Gauge (0.019")

Standard residential gauge. Good balance of performance and cost. Minimum recommendation for Gulf Coast standing seam.

29-Gauge (0.014")

Budget gauge. Dents more easily, more oil canning, lower wind resistance. Not recommended for primary residences on the Gulf Coast.

Coating System

The paint system determines color retention and salt resistance. PVDF is recommended within 5 miles of saltwater and for dark colors.

PVDF (Kynar 500 / Hylar 5000)

Premium coating. 30-35 year color warranty. Best UV and salt resistance. 15-25% more than SMP.

SMP (Silicone-Modified Polyester)

Standard coating. 15-25 year color warranty. Adequate beyond 5 miles from saltwater with light colors. Budget-friendly.

Fastener Material

Includes clips (for standing seam), screws, rivets, and all attachment hardware. Coastal proximity drives this choice.

316 Stainless Steel

Maximum corrosion resistance. Required within 1,500 feet of saltwater. Recommended within 1 mile.

304 Stainless Steel

Good corrosion resistance. Suitable for moderate zone (1,500 feet to 1 mile). Cost-effective coastal upgrade.

Galvanized / Zinc-Plated

Standard inland option. Acceptable beyond 1 mile from saltwater. Not recommended for coastal installations.

Underlayment

The secondary waterproofing between panels and deck. Self-adhering membrane at eaves and penetrations is code-required in most Gulf Coast jurisdictions.

Full Self-Adhering Membrane

Complete coverage. Maximum protection. Recommended within 1,500 feet of saltwater and for severe wind zones.

Hybrid (SA at Eaves/Penetrations + Synthetic Field)

Standard recommendation. Self-adhering membrane at eaves, rakes, valleys, and penetrations. High-quality synthetic in the field. Meets most code requirements.

Synthetic Only

Budget option. May not meet code in some Gulf Coast jurisdictions. Not recommended for coastal or high-wind zones.

Distance from Saltwater

This determines your coastal zone and affects warranty coverage. Measure from the nearest saltwater body (ocean, bay, tidal river).

Within 1,500 feet

Severe zone. Requires aluminum substrate, 316 SS fasteners, PVDF coating.

1,500 feet to 1 mile

Moderate zone. Galvalume acceptable with PVDF and stainless fasteners.

More than 1 mile

Standard zone. Full range of material options available. Salt-specific upgrades optional.

Metal Roof Specification Builder