Aluminum and vinyl sidings - don't peel and don't need painting for a long time, but both kinds will definitely oxidize (or "chalk") due to sunlight and weather breaking down their pigments. Eventually, oxidation will destroy the factory-applied paint.
These kinds of siding also discolor when they collect coatings of soot, industrial sulfur, pollen, rust, and especially mildew, either in shadowed areas or where water runs down.
However, siding's color and luster can last indefinitely if it's kept clean and waxed The Institute of Vinyl recommends yearly cleaning in order to keep warrantees valid on vinyl siding.
Unfortunately, delaying the cleaning of siding has consequences. The longer the job has been put off, the more difficult it is to remove soil. Multiple scrubs may be required.
When we clean aluminum and vinyl siding, we scrub with specially formulated biodegradable cleaning solutions that are meant for vinyl and aluminum. We use airless sprayers to apply it, reducing overspray and runoff.
