We have successfully painted our bathroom (not because of damage, but because it was dated) and used Wilkinsons kitchen cupboard paint. Having used it before on kitchen cupboards with a texture thought it would work well, and it has. We made sure all surfaces were sound, clean and dry and it covered well. Masking off took longer than painting. We now have a nautical themed loo....... All the best.
------------- better a rainy day up a hill than a sunny one in the office