If you are considering a metal roof to replace your current roof, it is a good investment. Metal roofs can last a long time and typically do not require any major maintenance. However, that does not mean that your metal roof will be entirely damage-proof. Here are some things that can cause damage to a metal roof, most of which you can avoid.
Hail up to the size of a golf ball or a tangerine can do damage to other roofs, but barely makes a dent in metal roofs. However, if you have a freak storm that delivers softball-sized hail, you should definitely check your roof. Hail this big will make some obvious dents and possibly a hole or two in your metal roof. Hail this size hurtling downward at high speeds is about the equivalent of chucking small boulders at the roof.
Tornadoes and Hurricanes
Except for some of the more extreme hurricanes and tornadoes, these storms are not likely to directly impact a metal roof. Indirectly, they can hurtle objects against the roof. Then you might want to check the damage after the tornado or hurricane has passed over.
Bullets will put holes in just about anything, including metal roofs. The bigger the bullets, the greater the damage, too. If someone starts shooting a gun in your neighborhood, a stray bullet can hit your roof and require some metal roof repair right away. Just make sure a police officer documents the damage before you have it repaired. You might be able to get reimbursed from the victims compensation program in your area (if applicable).
While it is highly unlikely that anything would fall from space or from the sky and damage your roof, it is not entirely improbable. Some homeowners over the years have had everything from defunct satellites to airplanes crash-land into the roofs of their homes. If it does happen, the damage may be covered by your homeowner's insurance, since this is clearly a bizarre situation and very damaging to your roof and your home.
Pretty much anything that can be hurtled through the air and lobbed at a metal roof and that is of reasonably large size can create damage in a metal roof. Of course, that would be the same for any other type of roofing material as well. Repairing these damages to a metal roof is a little different, but no less important than if you were repairing equal damage to asphalt shingles, wooden shingles, etc.