Oxidation is that chalky, powdery film that leaves siding looking dull, faded, or unevenly colored. It comes from years of UV exposure, and a standard house wash alone will not take it off.
Homeowners whose siding still looks tired after a wash, anyone with chalk coming off on their hand, and houses being prepped for sale or for paint.
Oxidation has to be dissolved, not scrubbed off. We apply a treatment made for chalked surfaces, work it in gently, and follow with a standard house wash to rinse everything clean — no aggressive scrubbing or high pressure that would take off more of the surface than the chalk.
It is the surface of the siding breaking down under years of sun. The color pigment chalks up, which is why your hand comes away white or grey when you run it along the wall.
No. A house wash removes mold, algae, and dirt sitting on top of the siding. Oxidation is the siding itself, so it needs its own treatment.
The chalk is gone once treated, and UV has to break the surface down again before it returns — usually a few years, depending on how much direct sun that wall takes.