I've been asked to clean a slate roof.
It's under some oak trees.
Lichen and normal greeny stuff on it.
What's the best way to get it clean?
And what is a decent price psm please lads?
It's a regular window cleaning customer who doesn't trust many people on his property so wants me to do it been though it's not my area of normal work...
Any help much appreciated please.
TIA.
Darren