A metal roof can last anywhere from 15 to over 100 years, with an average of 50 years, depending on the material, installation, and environment. The specific metal is a key factor: aluminum roofs may last 20 to 45 years, while steel can last 30 to 60 years. Tin can last for up to 75 years, and more durable options like zinc, stainless steel, and copper can last from 80 to over 100 years. Factors that can shorten a metal roof's lifespan include living in a coastal region with corrosive salt air, improper installation (such as laying over old shingles), and failing to inspect and replace fasteners, which may wear out before the panels.

A properly installed, high-quality tarp can be left on a roof for up to 90 days. However, this is only a temporary measure and not a substitute for proper roof repair or replacement. Thinner tarps or those exposed to heavy wind and rain may not last the full 90 days, so it's important to monitor the tarp's condition to ensure it continues to protect your roof from the elements.

An improperly installed skylight could potentially impact your roof's warranty. This happens because roofing penetration is necessary during skylight installation. Check your warranty information to verify. In most cases, having skylights professionally installed with proof that flashing is being done to specifications can be enough to preserve your roof's warranty.

The number of snow guards you’ll need on your roof depends on factors like the type of roof you have, its slope, the orientation of your home, and the snow load in your area. A local roofing professional or the snow guard manufacturer can help you determine the ideal amount.