Chimneys are one of the major areas on a roof that are prone to leaking.
A chimney breaks up the normal construction of a roof and this demands good flashings around them … so that the roof remains waterproof.
On a typical metal roof to terrace style buildings, the chimneys are located along the side walls.
If this scenario describes your situation, then the You Tube video (that is part of my training series) will give you an idea of where leaks can come in and how it is repaired..
