Black stain on render

[deirdremckay]

Hi,Does anyone know what the black stain on the render on the back of our house is? The house was built in 1840 and i think the existing render is not the original render.
Any help is greatly appreciated as we are just about to spend a lot of money filling in the cracks on the back wall of our house.
Dee

 

[aockenden]

Sure looks like damp and mould to me

 

[a twig]

The proximity of that hopper and guttering to the staining would make that my first port of call, next time it is raining go out and take a look, probably a good chance that it overflows and splashes the wall