Painting a bathroom ceiling

A friend had asked me to paint his bathroom ceiling.

However, the current surface has a matt finish, probably emulsion, which is very badly crazed. I suspect it had been put on top of gloss or similar years ago.

He wants it emulsioned, but I am concerned that it will craze again. I do not want to go through the process of removing the current surface finish if I can avoid it. Any ideas?

I am thinking of suggesting that I apply an undercoat and a gloss finish. Do others think that this will work?

Thanks
Ray

Had a similar situation and I used an Alkali primer and then emulsioned over the top (adised by Crown techy) had no probs. If in doubt go on the Crown website and ring the tech support.