Chalk occurs on aluminum siding due to aging and weather effects. While aluminum siding is rigid and holds up well to the environment, chalk will show up eventually. Although it seems like a big job, getting rid of the chalk is surprisingly easy. Chalk removal raises the value of the home and is much less expensive than siding replacement. By following these simple steps, aluminum siding can easily be made chalk-free.
Get to scrubbing. Hand-scrubbing is very effective at removing chalk from aluminum siding. Thoroughly scrub the surface of the siding with a dual-sided sponge or scrub brush. Two washes may be necessary to remove the chalk.
Try a power washer. A cold water power washer is a machine that hooks up to a garden hose and pressurizes the water for a powerful flow, making cleaning tough projects more simple. Power washing blasts off chalk that hand scrubbing can miss. Most hardware stores sell power washers, as well as major retail stores in the gardening department. You can also rent a power washer. Remember to follow all safety instructions that come along with the power washer, as the pressure of the water coming out can be dangerous and cause injury.
Gently hose off the siding with cold water to remove all the chalk that is loose and any residual cleaning products.
Check for additional chalk. Rub your hand over the aluminum siding. If your hand has white powder on it, there's still chalk on the aluminum siding.
Use a good primer. Keep in mind that it is difficult to completely remove all the chalk from aluminum siding. If after two tries of hand-scrubbing or power washing there is still chalk on the surface, simply use a primer before repainting the aluminum siding. The primer should be 100 percent acrylic and specifically manufactured for outdoor painting. This primer will cover up the chalk and allow the new paint to bond with the aluminum siding. Without the primer, the paint will not bond, causing it to look blotchy and uneven.