Before now, I've sprayed Virosol on a pvc clad exterior wall and then brushed off with a sill brush and water fed pole. Worked on a smooth surface such as upvc but it was still hard going.
Is there a better way for cleaning algae off a rendered walled house as I don't fancy brushing such a large expanse with a sill brush and not sure how effective Virosol would be on such an area?
And is it possible to do all that from the ground?