sazzafrazz, do you have a man hole in your roof? I know a few people who put things in plastic tubs that seal up well and put things like chrissy trees etc up in their roof. I'm considering doing it myself! Otherwise I have a lot of things in DF's shed in plastic tubs.
Oh I've just seen Rach has suggested the roof thing to! And here I was thinking I'd come up with a new one hehe!