We install more standing-seam metal on the South Bay climate than any other roofer in the county — Los Gatos, Naglee Park, Palo Alto, Mountain View, Willow Glen. The single question every coastal homeowner asks: "won't the salt air destroy it?" The answer depends entirely on what you install.

Galvanized steel — do not use on the coast

Standard G-90 galvanized steel corrodes rapidly within 1,000 feet of the ocean. Rust bloom appears in 2–4 years. Never spec this within a mile of the coast.

Galvalume — better, still not ideal

Galvalume (aluminum-zinc coated steel) resists corrosion 3–5x longer than galvanized. Good for inland Cupertino or Milpitas — marginal within a mile of the beach.

Aluminum — the coastal standard

Aluminum standing seam does not rust. Period. It's the only material we spec on oceanfront properties in Silver Creek, Rose Garden, and Willow Glen. Slightly softer than steel but with proper 24-gauge or 0.032"–0.040" thickness, it takes wind and hail without denting.

Copper and zinc — heirloom-grade

For estate work in Almaden or Saratoga, copper and zinc develop protective patinas and last 100+ years. Copper is $30–$60 per sq ft installed; zinc is $25–$45.

The finish matters as much as the substrate

Specify a Kynar 500 / Hylar 5000 (PVDF) paint system. Cheaper polyester paints chalk and fade within 5 years in coastal UV. Kynar carries 30-year finish warranties even in salt-air environments.

Fasteners are where most metal roofs fail

Standard screws with EPDM washers corrode in salt air. On coastal jobs we use only stainless-steel fasteners with silicone-based washers. This one detail is the difference between a 15-year and a 40-year roof.

Free coastal metal roofing consultation

Call (424) 777-1619 or email sales@californiafirstroofing.com.

Metal Roofing on the San Jose Coast: Does Salt Air Really Kill It?