September 28, 2026 · Job note
Red clay is not mildew
Bleach does not dissolve Georgia clay. Sound concrete can take a surface cleaner. A blush in the pores is said before the job.
Mildew likes shade. It is usually green or black and it smears. Red clay is orange, it tracks from the yard, and it sits in the pores of the concrete.
The house-wash mix is diluted sodium hypochlorite and a surfactant. It is for organic growth. It does not dissolve clay, rust, or old oil. Those are different steps, and some of them only lighten.
On sound concrete I can pretreat and run a surface cleaner. Sealed, spalled, or painted concrete may stay uneven. I would rather say that while we are looking at the photo than after the slab is wet.
A rust spot from a fertilizer or a well-water stain is iron. It is not clay, and it is not a reason to turn the pressure up.
The longer guide: How to tell red clay from mildew
Related: House washing, Roof soft washing, Work gallery, Send photos.