Cleaning your aluminum siding will be necessary after a period of time. Aluminum siding becomes faded and porous over time due to the sun and pollution damage. When the aluminun siding becomes porous it allows dirt and mildew to surface to the top. The first step in cleaning your aluminum siding would be to pressure wash on a low setting. If you need to do more after the pressure washing,
. then try scrubbing it with a detergent or trisodium phosphate and then hosing down with a low-pressure spray.
