An inspector will observe a home's roof from the ground. He doesn't actually have to climb up there. He may, but it's a long shot. For a thorough check, you'll have to call in a roofing contractor. There's more to consider here than just water leaks. The roof can be a party palace for local critters like birds nesting in a fireplace chimney, termites (yes, some varieties start at the top and work their way down) and roof rats. Raccoons, those naughty bandits, have also been known to excavate their way through a home's roof.