The roof in the picture isn’t just gravel, it’s got fist size rocks in it as well. Gravel alone I could understand.

Not in this part of the world though.

You would think the tar would ooze downward on very hot days. (Yes, we get them here.)

They probably could use shingles, there are plenty of surrounding houses with about the same pitch that do.

This is not a flat roof though, it’s sloped.

I wonder how they get them to stay in place. It’s not a steep slope, but it’s definitely not a flat roof. So far I have resisted the urge to ring the doorbell and ask about the roof.

This is in central Saskatchewan. Presumably those southwest roofs are flat - this isn’t.

I bought stocks of Ballard Power years ago when hydrogen cells were going to be The Next Big Thing. Not many stocks thankfully, because it slipped further and further and then got delisted. It seems to be one of those things like airships that gets revived every 20 years or so.