You don't need to be an expert to spot signs of damage on your panels—though some indicators are subtler than others. Some telltale signs include noticeable dents and scratches on the surface; cracks around edges which let cold air seep into your garage; rust patches which suggest water has infiltrated behind the paintwork.Beyond these visible issues though there’s another important factor: age. Over years constant use takes its toll making replacement necessary even if no major incident caused specific harm.