Metal Roofing Questions, Answered

Missoula-area cost guides put an installed metal roof at about $6 to $12 per square foot. Corrugated and other exposed-fastener panels run lower, around $3 to $6; metal shingles around $7 to $10; and standing seam around $9 to $12 (Homeyou). Your price depends on the panel, the roof's size and shape, the tear-off and any deck repair, and details like snow guards and ventilation.

One Missoula cost guide puts a 3,000-square-foot metal roof at about $19,900 to $31,300 installed (Homeblue). Keep in mind that a roof's area isn't the same as a home's floor area. Overhangs, pitch and a two-story layout all change it, so a 3,000-square-foot house might have a larger or smaller roof than that. An on-site measurement settles it.

It costs more up front, often considerably more than asphalt. In return, a metal roof can last several times as long, sheds snow, resists wind and fire, and needs little upkeep. If you plan to stay in the house for many years, the cost over the roof's life usually favors metal. If you're selling soon, shingles may make more sense.

It's a common guideline in building codes that if more than about 25% of a roof is repaired or replaced within a year, the whole roof may need to be brought up to current code. Whether and how it applies depends on your jurisdiction, so check with the local building department before planning a large partial repair.

Most metal roof problems come from installation, not the metal. On exposed-fastener roofs, the rubber washers under the screws age and screws can back out over time, so they need checking every few years. On any metal roof, poor flashing, missing underlayment, or no snow guards over a doorway cause most of the complaints. Oil-canning, a slight waviness in flat panels, is cosmetic. The panels themselves are the part that lasts.

Not on a house. Over solid decking with underlayment, and an attic and insulation below, rain sounds much like it does on shingles. Hail is louder on any roof. The noisy metal roofs people remember are on open-framed barns and sheds with nothing under the panels.

Yes, snow slides off metal, and that's mostly good: less weight on the roof and fewer ice dams. The catch is that it can let go all at once. Snow guards hold it on the roof so it melts off gradually, and they belong over doors, decks, walkways, driveways, lower roofs and anything else it could land on.

No. Metal roofs don't make a strike more likely. If lightning does hit, a metal roof is noncombustible and spreads the energy out, which is safer than a roof that can catch fire.

Standing seam roofs are commonly expected to last 40 to 70 years. Exposed-fastener roofs commonly last 20 to 40 years or more, depending on the panel, the finish and fastener upkeep. Asphalt shingles are typically replaced after 15 to 30 years.