What's the difference between standing seam and stone-coated steel?
Standing seam means continuous vertical panels with seams that lock above the water line and hidden clips underneath. Stone-coated steel is a modular product: pressed steel panels with a granule surface, shaped to mimic shakes, tiles or architectural shingles.
How does metal compare with asphalt on price?
Up front, metal is the expensive choice: the Cost vs. Value report shows the metal reroof well ahead of asphalt for the same defined job. Standing seam tends to cost more than stone-coated steel. Instead of a price per square, here is what changes the bid.
What changes the price of a metal roof?
- Material choices: steel vs. aluminum, panel gauge, coating
- How cut-up the roof is: valleys, hips, dormers, chimneys
- Tear-off: number of old layers and decking condition
- Minimum slope for the chosen system
- Staging: long panels and tight lots don't mix
How long does it last, and is it fire-rated?
Per InterNACHI, metal roofs last roughly 40 to 80 years; asphalt shingles about 20 to 30. And metal shingles or sheets are among the Class A roofs named in the state's Safer from Wildfires program.
Does a metal roof in the Bay Area have to be a cool roof?
Cool-roof rules depend on climate zone: San Francisco, the Peninsula, Marin and bayside East Bay cities are mostly in zones 2 and 3 with no prescriptive rule, while the South Bay (zone 4) and inland Contra Costa and the Tri-Valley (zone 12) require rated products on qualifying reroofs. See the CEC compliance manual.
What matters locally?
Across the region, three things decide whether metal is worth it: wildfire exposure (Marin, the East Bay hills, wine country and the Santa Cruz Mountains foothills), heat and cool-roof rules (the South Bay and inland East Bay), and salt air on the coast. Each regional guide covers the local version of that trade-off.
| Region | Main metal-roof question | Guide |
|---|---|---|
| San Francisco | Flat roofs and salt air | sfroofreplacement.com |
| San Mateo County | Coastal coatings, HOA rules | sanmateoroofreplacement.com |
| Marin County | Wildfire and tree cover | marinroofreplacement.com |
| East Bay | Hills fire zones, inland cool roofs | eastbayroofreplacement.com |
| South Bay | Heat, cool roofs and solar | southbayroofreplacement.com |
| Sonoma and Napa | Replacing shake after fire seasons | northbayroofreplacement.com |
What should be on a metal-roof bid?
On each estimate, look for the exact panel system, panel thickness, coating type, underlayment, Class A assembly and the length of the workmanship and finish warranties. Our quote checker covers the rest. For your actual price, request a free written estimate: a licensed roofer measures the roof and prices your exact scope.
Related: what drives roof replacement cost, roof size estimator, Class A roofs.
Every roofer we work with is licensed, insured and highly reviewed by Bay Area homeowners.
Get a free replacement quoteFrequently asked questions
How long does a metal roof last?
InterNACHI estimates 40 to 80 years, compared with about 20 to 30 for asphalt shingles.
Does a metal roof need a different contractor?
It needs a licensed C-39 roofer experienced with the specific panel system. Ask for examples of their metal work.
Where in the Bay Area does a metal roof make the most sense?
Usually in wildfire areas and hot inland zones, where Class A and cool-roof ratings matter. On the foggy coast, coatings and warranty terms decide it.
Sources
- Cost vs. Value 2025 report (JLC / Zonda)
- InterNACHI: life expectancy of roofing materials
- CDI: Safer from Wildfires
- CEC 2025 Single-Family Compliance Manual, ch. 9
- California Residential Code R908 (reroofing)
- CEC: climate zones
- CAL FIRE: fire hazard severity zones
Sources reviewed November 12, 2026. Figures are published estimates and official fees, not quotes. Confirm prices, permits and requirements with your contractor and building department. This page is general information, not legal or insurance advice.