On Mon, 10 Dec 2018 12:29:08 -0000, Tim Lamb
wrote:

Umm.. Cement bonded asbestos roofing *explodes* when heated. My
assumption is that this is due to steam from trapped water.

I don't know why it explodes but as kids we would seek out the dimpled
bits of cement bonded asbestos panels to chuck on the bonfire.

AJH