I know your post was a while ago but wondering if you had any luck resolving it?
We've recently had a colorbond roof installed and have the same issue, banging popping all day and all night. Woken up at 4am the past 5 mornings in a row to a loud bang.
I am aware of thermal expansion etc, but there is no temperature change between midnight and 5am so why the noises..[/quo
Did you find out what the problem was mate?
Not yet…