Hi fellas,
Got a quote to do, big black run marks down the front of a house, apparently its staining caused by slate?
Never heard of that ever.. was thinking HF and a wash down?
I was just curious if anyone has come across the slate thing before or is it just normal staining over time? the run marks are very prominent. they look like stains from leaky drainpipes but they are no where near the downipes..
Cheers