Aluminum vs steel roof at a glance
Steel roofing for homes is coated steel, and HomeGuide calls Galvalume one of the most popular choices away from the coast. Aluminum is solid aluminum sheet, nearly always painted. Here is how they compare on a Florida house.
| Feature | Galvalume steel | Aluminum |
|---|---|---|
| What it is | Steel with a 55% aluminum-zinc coating | Solid aluminum sheet, usually PVDF-painted |
| Thickness in a Florida approval | 24 or 26 gauge | .032 or .040 in. |
| Weight (Englert) | 1.5 to 2 lb per sq ft | 0.5 to 0.75 lb per sq ft |
| Salt-air warranty (Gulf Coast Supply) | None within 1,500 ft of breaking surf | Covered up to the water's edge |
| Dents | Resists denting better | Dents more easily |
| Installed cost (HomeGuide, Nov 2025) | $500 to $1,300 per 100 sq ft | $700 to $1,700 per 100 sq ft |
Thicknesses are from Tri County Metals' 2023 Florida approval. Dent notes are from Englert and Sheffield Metals.
Galvalume steel: AZ50 and AZ55
Galvalume is steel coated with an alloy that Englert puts at about 55% aluminum, 43.5% zinc and 1.5% silicon. Englert says the zinc keeps scratched spots from rusting.
The AZ number is coating weight. Sheffield Metals, a coil supplier, says AZ50 means 0.50 ounces per square foot across both sides and is typical for painted sheet. AZ55 carries 0.55 ounces and is typical for bare, unpainted panels.
Florida's code sets AZ50 Galvalume or G-90 galvanized as the minimum for steel roofing. Tri County Metals' approval lists painted AZ50 or AZ55 steel, and Metlok (a sponsor of this site) uses AZ50 Galvalume.
Aluminum roofing
The Aluminum Association calls aluminum rustproof, lightweight, strong and corrosion resistant. It says more than 60% of the aluminum used in new buildings comes from recycled material.
Florida's code sets aluminum minimums at 0.024 inch for roll-formed panels and 0.019 inch for press-formed shingles. Tri County's approval uses .032-inch aluminum for 5V and snap-lock panels and .040 for its 1.75-inch seam.
Aluminum comes as standing seam, 5V and interlocking shingles. Interlock, an aluminum interlocking shingle sold through independent installers, carries Florida approval FL7263-R7. Our interlocking metal roofing guide covers it next to Metlok's steel system.
Salt air: the coast vs inland Orlando
This is the real dividing line in an aluminum vs steel roof decision. Gulf Coast Supply's 45-year Galvalume warranty doesn't cover panels within 1,500 feet of a coastline with breaking surf. The limit is 800 feet from a large bay, inlet or canal and 400 feet from a marsh or tributary.
Sheffield says Galvalume substrate and paint warranties aren't available within 1,500 feet of a coast. Englert calls aluminum extremely resistant to seawater corrosion, and says its coastal finish warranty isn't provided for steel panels.
Aluminum has no such setback. Gulf Coast's OceanGuard aluminum warranty excludes only panels installed beyond the water's edge. Gulf Coast also lists a 50-year saltwater paint warranty for Armored Coast, a painted steel line, so ask whether a coastal steel option exists.
An Orlando subdivision is miles outside those coastal setbacks. If you're on a lake or canal, ask the panel maker in writing whether its setback applies to your address.
How it's attached: fasteners and mixed metals
Both metals use the same clips, screws and profiles, but the fastener metal has to match. Florida's code says to use the maker's fasteners. Without a maker spec, steel roofs get galvanized fasteners, aluminum roofs on aluminum supports can use aluminum, and stainless works with all.
Galvanic corrosion
The Metal Construction Association explains that two different metals joined by rainwater can form a galvanic couple. The less noble metal then corrodes faster. Salt water makes a strong electrolyte, which is why this matters near the coast.
Its classic example is a galvanized nail in an aluminum roof: the zinc wears off fast and the nail rusts. An aluminum nail in a galvanized roof poses no problem, and aluminum clips and clamps are compatible with Galvalume.
Copper is the one to watch. MCA says copper has a very severe corrosive effect on steel, aluminum and zinc, including runoff from copper plumbing and HVAC equipment. It also warns against treated lumber and graphite pencil marks on aluminum or Galvalume.
Florida wind ratings and dents
Thin aluminum isn't the weak link in wind on paper. In Tri County's approval, .032-inch aluminum 5V with screws every 6 inches is rated -150 psf. Its 26-gauge steel 5V at the same spacing is rated -120 psf.
Each assembly uses its own specified screw, so the rating belongs to the tested system, not the metal. Interlock lists -187.5 psf for its aluminum shingle and slate profiles. Ask for the approval number and system row on any quote.
Dents are a different story. Englert says aluminum is more prone to denting than steel, and Sheffield says it dents more easily during and after installation. If kids, ladders or falling limbs are part of life at your house, steel holds up better.
Look, heat and paint finish
From the street, an aluminum vs steel roof looks the same in the same profile and color. Englert says aluminum panels are almost always painted with PVDF or SMP coatings. Unpainted Galvalume is a steel-only option; Gulf Coast offers no warranty on bare aluminum.
Heat affects the two differently. Sheffield says aluminum expands and contracts roughly twice as much as steel, and recommends expansion clips on longer panels. With Orlando's 92.0°F average July high (NOAA 1991–2020 normals), ask how long panel runs are handled.
Color drives cooling for both. The EPA says cool roofs can cut peak cooling demand 11% to 27%.
Maintenance near the coast and inland
Both Gulf Coast warranties ask owners to rinse the roof with fresh water twice a year to clear salt residue. They also require records of that maintenance. Inland, the yearly debris check and inspection assumed in MCA's service-life study is a sensible baseline.
Keep copper runoff, treated wood and stray fasteners off either metal. When a screw or clip is replaced, make sure it matches the original metal.
Lifespan and warranty
A study sponsored by the Metal Construction Association and Zinc Aluminum Coaters Association projected more than 60 years for unpainted Galvalume standing seam. Its 14 sites spanned five U.S. climate regions, and the article on it doesn't address salt air.
Gulf Coast's OceanGuard aluminum warranty covers paint cracking and peeling for 50 years, chalk and fade for 35, and perforation for 20. It covers hidden-fastener systems only; exposed-fastener aluminum is excluded.
Orlando roofers word coastal coverage their own way. J&M Roofing offers an OceanGuard treatment with a 25-year saltwater warranty. Mid Florida Exteriors lists 25 years on corrosion and 40 on paint.
Aluminum vs steel cost
HomeGuide (Nov 21, 2025) puts installed aluminum at $700 to $1,700 per 100 square feet and Galvalume at $500 to $1,300. Englert says aluminum systems cost 20% to 35% more than steel.
Not every guide agrees. Angi (updated Sep 25, 2026) lists aluminum materials at $4 to $11 per square foot and steel at $6 to $16. Sheffield's 2022 material prices put painted Galvalume at $1.75 to $2.35 and aluminum at $2.20 to $3.00.
Orlando roofers tend to price by system, not metal. See metal roof cost in Orlando for local ranges, and our metal roof gauge guide for how thickness moves the price.
Which fits an Orlando house
Pick Galvalume steel if
- Your home is inland, as every home in Orange, Seminole and Osceola counties is.
- You want the lower price and better dent resistance.
- You like the bare Galvalume look, or want the widest color and gauge choice.
Pick aluminum if
- The house is within the salt-water setbacks above, such as a beach or Intracoastal home.
- You're re-roofing a mobile home; HomeGuide calls aluminum popular there.
- Weight matters to the structure.
Still choosing a system first? Compare all metal roof types, or read our standing seam guide, which comes in both metals.
Orlando roofers that install each metal
On the steel side, Metlok, one of our sponsors, makes its shingle panels from AZ50 Galvalume steel.
Sponsored
Metlok
Best for: A metal roof that looks like shingle, slate, shake or tile
- Metal system
- 26-ga Galvalume steel shingles
- Profiles
- Shingle, Slate; Shake and Barrel coming
- Warranty
- 50-yr limited lifetime, labor + materials
Metlok makes its own steel shingles in its own factory, and its own crews install them, so one company answers for both. Each panel locks to its neighbors on all four sides, so no screws show on the finished roof. Its Shingle and Slate panels carry Florida Product Approval FL47482.
Shingle and Slate profiles are available now, with Shake and Barrel listed as coming soon, in colors such as Carbon Gray, Coastal Drift and Tuscan Clay. November offer: $3,500 off a new Metlok roof signed by Nov 30.
Watch for: Only 6 Google reviews so far, and it's one product line. For standing seam, see the next pick.
Source: metlokroofing.com (products, warranty), Metlok's Google profile and November offer terms, checked Nov 8, 2026
These roofers on our list offer aluminum as well as steel, per their own websites:
- T Mark Metal Roofing: aluminum standing seam, which it calls ideal for coastal regions, plus Galvalume 5V.
- Roof Bear: lists aluminum, galvanized steel and Galvalume steel among its systems.
- Mid Florida Exteriors: steel and aluminum panels, including aluminum roof-overs for mobile homes.
- J&M Roofing: offers OceanGuard for coastal homes. Its "aluminum standing seam" is described as zinc-aluminum coated steel, so ask which metal you're getting.
See every installer on our list of the best metal roofers in Orlando.
Sources: Gulf Coast Supply, 45-Year Galvalume Warranty (sample); Gulf Coast Supply, OceanGuard Aluminum Warranty (sample); Gulf Coast Supply, Product Warranties; Gulf Coast Supply, OceanGuard Aluminum Roofing; Metal Construction Association, Dissimilar Metal Corrosion in Roofing Installations (Jun 2016); The Aluminum Association, Building & Construction; Englert, Steel and Aluminum Roofing; Englert, Galvalume vs. Galvanized; Sheffield Metals, Galvalume Steel vs. Aluminum (Jul 14, 2022); Florida Building Code 2023, Chapter 15; Tri County Metals, FL36904-R11 evaluation report (issued Jun 24, 2024); Interlock, Florida Product Approval FL7263; Metlok, Products and FAQ; Construction Specifier, MCA and ZAC service life study (Dec 9, 2014); HomeGuide, Metal Roof Cost (Nov 21, 2025); Angi, How Much Does a Metal Roof Cost? (updated Sep 25, 2026); NOAA 1991–2020 Climate Normals, Orlando International Airport; EPA, Using Cool Roofs; T Mark Roofing, Roof Systems; Roof Bear; Mid Florida Exteriors, Metal Roofing; J&M Roofing, Residential Metal Roofing Systems. Checked Nov 8, 2026.
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