I've just landed a contract to clean the windows in a large public building.

Most of the upper windows have bars over the window frames and, when I priced the job I thought a standard 10inch WFP brush would do the trick. I did the first clean this morning and, unfortunately, the bars stop the brush head from sitting squarely on the glass.

My question is - where can I get a brush that is less than 10 inches wide (8 would be best)?