Can anyone tell me how to install a colorbond roof on a cubby. The existing one is going rotten (the makers used untreated pine) although we painted it as soon as it was built. Do we need to remove the wooden roof before installing the colour bond? Also advice on a filler to fill softened wood in the railings etc without having to take the whole thing down. It’s only a couple of years old. We have a tarp over it ATM. Am in Queensland. Thank you all. Jane