What to do to prep bead board ( wood finish) for painting in bathroom

If it is painted already, wash it to make sure it is clean. Find out whether the paint is acrylic or oil that is already on it. If oil, and changing to acrylic, prime first.

If it is raw wood, then sand until smooth. Wipe off.

Prime it with a really good quality primer like 123, from hardware store.

I recommend PPG/Porter Paints Advantage 900 paint, in semi-gloss sheen. It is very, very durable.

Put thin coats on, just one a day, and let each coat dry overnight.

In the end, once the color has built up sufficiently, you will not need to put a sealing poly coat on.

***Don't use the bath, keep it dry for the entire week you work on it. Give it two days after final coat, before resuming bath activities.

The bead board has dark maple finish with small groves. Can I wash prime then paint?