We cleaned a white tile roof a couple months back. Had to go back the following day to get the check. I noticed a few areas that looked like they needed to be re- hit but didn't have my rig. I knew we had another to do down on the same street the followingweek and figured we could just stop and hit it. During those few days we had a couple of our wonderful Florida rains. When we drove back out the following week the spots were gone and that white roof was whiter than newly fallen snow. Even after all these years of doing this I'm still amazed sometimes.
We cleaned a red barrel tile roof last week. The next day it rained over an inch within 30 minutes. The customer called back saying there was red blood all over her pool deck. The gutter downspouts had flooded her pool deck. Fortunately the pool had a lip that kept the water out. The water had receded by the time we got there but the white patio was red from the tile pigment. We pressure washed the tile pigment off her patio off and she was happy. Lucky we were in the area that day.
We cleaned a red barrel tile roof last week. The next day it rained over an inch within 30 minutes. The customer called back saying there was red blood all over her pool deck. The gutter downspouts had flooded her pool deck. Fortunately the pool had a lip that kept the water out. The water had receded by the time we got there but the white patio was red from the tile pigment. We pressure washed the tile pigment off her patio off and she was happy. Lucky we were in the area that day.
Red CLAY Tiles are the absolute worst! Count on them to "bleed" color. It is not to worry, it is merely the oxidized clay coming off, not like we are "taking the color out" of the roof tiles.
We always tell the customers to expect a little of it
I actually tell customers now that they may see see some light brown streaking.. and that mother nature will rinse off that dead algae...
I sell it to them by saying we try to use as LITTLE chemicals as possible, so rather then adding more to rinse, we let rain do it... Most like that explanation... I tell them that if after a rainstorm it isn't gone, to call us and we will touch up...99.9% of the time, the rain does the job..
this way i actually can save on chemicals, and the possibility of dead landscaping from using too much chems..
After finding the RCIA, I did a bunch of roofs in my neighborhood, real cheap. one roof I didnt spray too well and watch it come clean any way after a month or so. We wait for the roofs to dry now and check for touchups and hit the brown stains a second time.