A flight will show you cracked flashing, lifted tiles and standing water. It will not tell you what the deck underneath is doing. Here is where the line sits.
An aerial roof survey is a visual inspection from a better angle. It finds the things you would find from a ladder, faster and without the permit — and it finds them across the whole roof rather than the two corners the ladder reached.
What it cannot do is see through the covering. Saturated insulation, a rotting deck, a failed vapour barrier: none of that is visible in daylight imagery. A thermal pass narrows it down by showing you where heat and moisture are behaving oddly, but confirming it still means opening something up.
We say all of this before you book, because a survey that answers the wrong question is an expensive way to feel reassured.
