Peter - Terrible luck with the flood. I've always been extremely glad to live at the very top of a hill, but after the clean-up contracts from the Carlisle floods I can fully understand and sympathise (?sp) with what you are feeling. Mother nature is a wonderful thing when in a good mood, but...
Austin - Sounds like we've got the same trouble up here too! The roof on our store is corrugated asbestos/cement fibre/whatever sheets with bloody great CI roof lights set in. Sadly one of the runs of Purlins has gone rotten and is collapsing, taking 2 of the lights with it. Managed to score a huge heap of cheap tin sheets off a farmer, so it'll be cheap enough to do but still an absolute pig of a job! Cheers and good luck, Scruff.