I have a high pressure telescopic lance but it's too heavy and overkill to softwash With, I think I might use my WFP but block one on the brush holes, I need it to treat a slate roof which is quite flat, so I will just start at the top spray a strip, turn of the tap I've fitted on my hose then brush that in........then repeat as I clean down the roof.
I think the hardest part of this job will be making it last a day, it's been priced on a day rate plus chemical cost so we have to be their 6hrs. so if we have to muck about a bit it will not be a problem.