We did a complete tear-off, and you know what they found under those 3 layers of shingles? Three holes in our roof. Right over Adrian's bedroom. Which may explain why his room was SO MUCH COLDER than the rest of the house last winter. One of the holes was big enough to put a basketball in. And I took pictures. So here they are, for your viewing pleasure.
Hole number one. AKA the really big one. And if you look up towards the crest of the roof, you can see hole number two.
Thankfully, all have been repaired and we have a new roof on top of them.
It just goes to show: you never know what's under there!