This rule is a legal stipulation that any roof over the age of 15 years must be inspected and re-certified to meet current code requirements. Upon reaching a 15 year lifespan, an advanced commercial roofing professional must inspect the roof and be satisfied that it has a minimum of five more years of operation left. Under previous laws, any roof over 15 years old had to be replaced as insurance providers would refuse to cover anything older than that. Thankfully, laws were recently changed to offer businesses better cost-efficiency from their roofs with an increased legal lifespan.