How do I clean black water stain off white siding?
I'm helping clean the siding of a church with vinyl. This black stain appears to be from the roof with rain runoff. I've tried the vinyl siding spray cleaner, which does a good job on mold and dirt in general. However, it isn't really working on this. I've also tried mixing water with LA Totally Awesome cleaner (more than 50/50 mix of cleaner), as well as Purple Power. I use a scrub brush on an extension pole, and it does help fade it some. However, it is still there and obvious. Are there any better options for this? Should I try 100% cleaner vs mixed with water?
**Hurricane Helene took off the added roof they had built, and the contractor just repaired the older trailer-style roof that was originally under that. I don't know why, or the history, but now it causes this water staining issue. We are in the process of painting the deck as well.
