The gravel stabilizes the tar somewhat. But yes. And gravel washes off the roof too. And then the roof leaks the next time you get rain. They’re typically initially installed with hot asphalt and then patched with tar until the homeowner gives up and buys shingles. There’s a good reason you don’t see gravel roofs very much.
You would think the tar would ooze downward on very hot days. (Yes, we get them here.)
The gravel stabilizes the tar somewhat. But yes. And gravel washes off the roof too. And then the roof leaks the next time you get rain. They’re typically initially installed with hot asphalt and then patched with tar until the homeowner gives up and buys shingles. There’s a good reason you don’t see gravel roofs very much.
The roof in the picture isn’t just gravel, it’s got fist size rocks in it as well. Gravel alone I could understand.