Best way is this ...
Mrs. Custy "I've had the builders in (ooh er missus) and they were sealing the walls and have got some aquaseal on my windows what should I do?"
Mr. Windy "Well, madam, to satisfy you properly and thoroughly so that you recommend me to your friends - so that I can do them later - takes a lot of preparation; it's a long hard job that needs a lot of lubrication and steady rhythmic strokes with my blade to get the best results. It will take a lot of time and I haven't got the necessary patience, desire or equipment! - So get the builders back in to finish the job they started and sort you out properly."