Stucco and paint oxidation

I just started washing this stucco house. I started up on the roof cleaning the chimney. I noticed when I appplied my 4% hw mix and rinsed the water was yellow and took away some paint. It looks ok, but this house is like 7,000 sqft. I don’t want to be responsible for painting it. Is this oxidation? Is there a certain way I should clean it? Proceed as normal?

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Or is this a case of walk away fast?

The rest of the house doesn’t look that dirty. Regular hw mix should be fine. But do an inconspicuous area first and see. 4% mix going to take the paint off a lot of things.

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4% mix on the entire house?

7k sq for house I imagine there is tons of landscaping. I’d be careful…that’s a hot mix to be spraying into the air.


It’s just bad failed paint. Just show the home owner how you can remove the paint with your fingers. Pretty self explanatory after that . They need a painter. One side probably looks worse than than the other because it spends more time in the sun

I’m confused did you notice it while you were rinsing the house with water. Or did you spray 4percent sh on that house ?

I noticed it before I touched anything. I rubs my finger on it bc it looked chalky. I’ve used 4% on several stucco homes entirely because of how porose it is, it usually needs a hotter mix. I’ll try something weaker but the paint is definitely oxidized. I just washed under the patio area and no issues with 4%.

I talked to the home owner and she says to proceed with just the back and see what happens. So far so good. I did turn down the % now but it’s the same issue.

You guys must have something different than I see. 99.9 homes in Florida are stucco but they are all painted over. Its the algae on the paint we’re trying to clean not the stucco behind it. If I was to put 4 percent SH on a yellow stucco home down here it would discolor the paint on many homes.

Some are painted over, others are mixed in. I don’t mind cleaning the painted over, the mixed in is like cleaning vertical concrete. It’s a pain

I can honestly say I’ve never seen that before on a home. Must not be something they do down here