Composite decks have only been around for a short period of time maybe around 15 to 20 years. most of the newer decks we can clean with a 1% mix no problem but the older ones i feel have issues. Its like the mix will bleach out the pigment / color of the deck and customers are getting upset from time to time. we try watering down the deck or even tarping it but if any mix gets on the deck it cleans/ fade the color. Then we spray the whole deck and it might still not come out right.

All the online manufactures dont say anything about using bleach to clean mold. they say use soap and a brush or somthing of that nature. 

Have any of you guys delt with this issue before. any guidence