What Are the Dangers of Metal Roofing?

Corrosion

• Exposure to water, natural salts and other chemicals from the atmosphere can cause a metal roof to erode due to corrosive chemical processes. Combining different types of metal during repairs can cause electrolytic reactions, speeding up the corrosion process and leaving metal roof panels rusty and ineffective at keeping water out of your home. Corrosion also occurs if builders use the wrong type of nails during installation or place nails in incorrect positions.

Snow Shedding

• Metal roofs shed snow by allowing it to build up in time and then slide off down the roof’s slope. Slick metal panels shed more snow than do shingles and tiles, which may require homeowners to use roof rakes to prevent ice dams. A metal roof can produce a small avalanche of snow at any time. Opening and closing exterior doors can cause snow and ice to dislodge on the roof, placing people entering or exiting the home in danger of being struck from above by falling snow or ice.

Conductivity

• Unlike most other roof types, metal roofs conduct electricity. This poses a problem if a metal roof is struck by lightning. While the chance of a lightning strike depends on location and the height of the home, a metal roof struck by lightning in one spot becomes electrified throughout its surface. This creates intense heat and produces a deadly shock for anyone or anything in contact with the roof's metal panels at the time of the strike.

Financial Risk

• Installing a metal roof places your home renovation or construction budget in danger. Metal roofs are among the most expensive roof types. While they require very little maintenance, it may take many years for a high-quality metal roof to pay for the difference between its cost and the cost of a roof made with another material. If your budget is tight, estimate the cost of several types of roofs and compare durability to determine if you can afford metal in the long run.