I need to quote to clean a 1st storey conny roof, hipped plastic roof about 20' by 10' The roof is about 20' from the ground. The ground on the front is grass, but the right hand side is slippy sleepers and shingle. The left hand side is brick wall and can access no probs, the right hand side is all windows but can rest ladder against house wall and do from there. I should be able to clean the hipped end of the roof from the right hand brick wall with a ladder standoff. My gut feeling is to quote £100, mainly danger money as would probably have quoted £50-60 if ground level with no awkward access issues. I am just starting out though so have no idea Is this too high or too low?