This may be a strange question but I was just reading the "Fitting a flexible flue liner PROJECT" and was wondering whether there is a particular reason for carrying the flue liner first onto the roof and then pull it down? It seems to me rather dangerous to get the liner on the roof. Couldn't you just carry a long rope and a pulley onto the roof? The pulley could be used to smoothly bend the rope towards the forecourt or backgarden where your helper could stand firmly with both feet on the ground and pull the liner upwards.
Has anyone tried such a variant or is this really a stupid idea?