Maybe you already knew this...but I didn't. It's illegal, in Massachusetts at least, to store propane "inside or on balconies above the first floor of any building or structure used for habitation".
Why did this come up? Well last week on that crazy hot day, there was a fire in Charlestown. A gas grill on a roof deck exploded. I was talking to Mike and he said that home owners insurance wouldn't cover it because the propane was illegally stored.
Here's the official statement from Mumbles.
So now you know....no propane on the roof.