noticed yesterday on my 1990 bessacar cameo a drip from my skylight, so I removed it to reseal, I have done this a few times but this time I noticed that the wood is completely rotten, almost compost like. I took a few ceiling boards off and noticed that they are all rotten, even the ones were the awning rail screws too. does this sound like a repair that can be done, I am pretty good at diy so don't mind the work, could just do with some tips.