I bought it to clean mold from an exterior wall but unfortunately it didn't succeed even at a distance of 2cm. I tried to clean dirty aluminum shutters and it didn't do a very good job either. Although the tool is not bad, it's not suitable for heavy-duty tasks. Its construction is relatively problematic, especially the container for the cleaning liquid. The part that attaches to the machine is difficult to put on and take off, and it's only a matter of time before the container's screw becomes loose and easily comes off. This can be solved by using some insulation tape on the thread. I have had it for about a year and a half and it works without any issues.