Aluminum siding is not affected by water and it does not rust. However, when aluminum comes in contact with air, it forms oxides. As a result, with the passage of time, the color of the siding fades out and it loses its sheen. Then the signs of wear and tear show up on its surface and it looks really ugly. For this reason, aluminum sidings require regular maintenance. Now, replacing an old siding with new one will prove to be quite an expensive affair. So, the suitable alternative is to add a fresh coat of paint on it.