The condition of your roof may not be apparent from the ground. It is wise to have the roof inspected for hidden damage or other issues even if you don't see a leak. A thorough roof inspection will also involve going inside the attic spaces to inspect the condition of the roof sheathing and other areas such as the areas in and around the soffits and fascia boards to look for overall condition and evidence of leaks. If a leak goes undetected it can cause major damage to a structure including deteriorating structural wood members and can also cause the buildup of mold. In these pictures, I was inspecting a condo and using thermal imaging I found moisture in the kitchen ceiling which only presented as a slight discoloration. Upon further inspection inside the attic space I found a leak from a roof vent penetration. There were no obvious signs of leakage from the roof, which is why a thorough inspection must be conducted in the interior and attic.