Metal Roof Types and Metal Roof Work
Metal Shingles and Shingle-Look Panels
Metal shingles are steel or aluminum pressed into individual pieces or short panels that interlock on four sides. From the street they read as asphalt, slate or cedar shake, which matters on a colonial or a Tudor where a ribbed panel would look out of place. Stone-coated steel adds a granule surface for a more textured look.
Michigan's code is stricter with metal shingles than with panels. They need a slope of at least 3:12, and a solid or closely fitted deck unless the product is designed for spaced sheathing. HomeGuide puts metal shingles at $6 to $14 per square foot installed, and metal slate at $600 to $1,400 per 100 square feet. Because each piece is small, a damaged shingle can be swapped out without disturbing a whole panel, which makes them easier to repair after a limb strike than long panels.
Exposed-Fastener and Corrugated Panels
These are the long ribbed or wavy sheets screwed straight through the face, each screw sealed with a rubber washer. Corrugated, 5V crimp and ribbed profiles all fall here. They're the cheapest metal roof, $5 to $12 per square foot installed in HomeGuide's figures, and HomeGuide also notes they need more maintenance and wear faster than standing seam or metal shingles.
The code sets their minimum slope by how the laps are sealed. Lapped panels with no sealant need 3:12; with applied lap sealant they can go down to 1/2:12. Panels can go over solid or spaced sheathing. Our view: exposed-fastener panels make sense on a garage, shed or back porch. On a house, the hundreds of washers are hundreds of future leak points, and most owners are happier paying for standing seam or shingles.
Metal Roof Over Shingles
Going over the old roof saves the tear-off and the dumpster. Michigan's code allows it in specific cases. A "complete and separate" roofing system, such as standing seam, that carries its load straight to the house's framing doesn't require removing the existing covering. A re-cover is still off the table over two existing layers or a roof that's water-soaked; that limit is explained on asphalt shingle roofing.
We'd still tear off on an older house. The deck under an old roof is the part nobody has looked at in decades, and covering it with a 50-year metal roof means you won't look at it for decades more.
Metal Roof Repair (Screws, Laps, Rust)
Most leaks on an older metal roof come from the parts, not the panels. Screws back out as the steel expands on hot afternoons and shrinks on cold nights, and the rubber washers dry out and crack. Lap joints lose their sealant. Cut edges and scratches that reach bare steel start to rust.
The repairs match the cause: new screws and washers driven straight and to the right depth, laps cleaned and resealed, rust sanded back and primed. A roof where most washers have failed is a candidate for a full re-screw. A roof rusted through in several places is a candidate for roof coating or replacement.
Standing Seam
Standing seam panels run from ridge to eave with raised seams and hidden clips, so no screws go through the face. The code lets them go as low as 1/4:12, flatter than any other metal roof, and HomeGuide puts them at $9 to $16 per square foot installed. Snap-lock versus mechanically seamed panels, gauge, finishes and snow guards have their own page: standing seam metal roof.
Why Ann Arbor homeowners call Ann Arbor Roofing Co.
- Written estimate, free of charge
- Shingle line, underlayment and ice barrier named in the price
- Deck repair priced per sheet before the tear-off
- One independent local roofer per request, not a call list
- No fee to the homeowner for the referral
What a Metal Roof Estimate Should Name
Two metal roof quotes can look alike and describe very different roofs. A useful written estimate spells out:
Base metal and coating
Galvalume, galvanized steel or aluminum, and the paint system on top.Gauge
the steel thickness. Lower numbers are thicker, and thicker panels dent and oil-can less.Profile and attachment
exposed screws, concealed clips, or interlocking shingles, plus the screw or clip type.Underlayment and ice barrier
Michigan's code requires an ice barrier along the eaves under metal shingles, the same as under asphalt (why, on ice dam removal).Trim and flashing
ridge, valleys, eaves, rakes, chimney and wall flashing, each as its own line.Snow control
metal sheds snow fast. Over a door, a walkway or a lower roof, snow guards belong in the quote; the options are on standing seam metal roof.
What Does a Metal Roof Cost in Ann Arbor?
HomeGuide's national range for a metal roof is $5 to $16 per square foot installed, with an average job around $23,800. Labor alone runs $400 to $800 per square. For a large house, the 2025 Cost vs Value report put a Detroit-area metal re-roof at $57,107, with 52% of that cost recouped at resale.
What drives the price:
Profile
Exposed-fastener panels cost least, metal shingles more, standing seam most.Metal
Galvalume and galvanized steel run $500 to $1,300 per 100 square feet installed; aluminum, copper and zinc cost more.Tear-off
Removing the old roof adds labor, though it's the only way to see the deck.Trim
Ridge caps, valleys, eave and rake trim and flashing at every chimney and wall are custom-bent pieces, and a roof with many of them costs more per square foot than a simple gable.
The longer life is what you're paying for. HomeGuide puts metal at 30 to 80+ years; the panels set the upper end and the screws and sealants set the lower one, so we'd have an exposed-fastener roof's screws checked every year or two.
For a full re-roof in another material, see roof replacement in Ann Arbor. If the roof is mostly flat, a membrane may beat metal on price; compare on flat roofing.