I noticed black mould on the wall near the gutter downpipe. There's some space between the gutter and the wall so I'm not sure how black mould appears on the wall.
The gutter is on one side of the wall (clean). The black mould is on the other wall of the corner.
What to do about it? I checked the gutter inside and it's clear
Photos
https://www.diy-forums.com/attachments/ ... -jpg.5968/