Hi all we tried to clean this roof today with some success but not finished yet. I would like some advice on where we can improve our way of doing the job. We started with 70ltr of water 30ltr of SH (10/11%) 17ounces of Green Wash. We sprayed the roof three times and still on some parts of the roof didn't come up clean. This roof is synthetic slate. I might add that we added more SH after spraying the first section. In all we used probably 35ltr of SH in the first batch. Should we rinse the roof while it is wet? All advice gladly
Thanks Michael, No it was the blue black staining that is still there. The pole was being used with a small brush and plastic scraper to remove lichen that was growing on and under the ridge tile.
I would give it a couple of rains then see what it looks like. I did a shingle roof last year and i kept spraying and spraying but the roof was still black. We had to pack up soon after becuase a major thunderstorm was getting ready to roll thru. So we came back the next day to finish up and the stains were gone. Sometimes it just takes a good rain.