i have notice the amount of stress my pole takes every day with summer being here now, most of all my custys are leaving there upstairs windows open, and i am having to push them closed with the pole, i would imagine this is when most pole breakages happen. i have one custy that was puzzled for weeks why her windows where closed every time she got home 
turn the flow right down and just clean the glass, no stress on pole then
i usualy do ian, but these houses are next to builders puting up new houses next to them, and are getting all the dust from lorrys tractors ect, every fortnight the frames and sills are covered in builders dirt, i should be charging them for first cleans every time
