Ste, as mentioned WFP is far safer with your feet on the ground however there is nothing wrong with the use of ladders if used correctly. Get in touch with a local professional wc and spend a few days with him (FOC) so he can share his experience with you. We can all tell you about ladders have to be at a 75 degree angle , tied off at the top, footed at the bottom ect,ect but in the real world ! At this time of year , surfaces are very slippery so don't risk life or limb by guessing . Ed