Spot around the roof line

[JJhome]

Dear all, we found this spot at the roof area & not sure what it is.

 

Could it be mold or dust/dirt? 

 

How do we remove or clean that spot?

 

Thanks

[Redbeard]

Although you have highlighted (?highlit?) the area the pic is not clear enough for me to see what the issue is which you are referring to. Perhaps the top-coat/paint has flaked off the render at the jct with the tiles. Is that what you mean?

[joe90]

Looks to me like mouldy/flakey paint on the render junction with the tiles, wire brush it off and re paint.