I got to repaint my washroom ceiling as the paint is peeling out and there are some black dots. I think they are molds or mildews. My friend suggest to use just Kilz oil base primer without top coat. Sounds right for humid environment. The Home Depot guy advised me to buy the Behr Premium Plus Enamel Undercoater Primer and Sealer followed by Behr Interior Sateen Lustre Enamel for Kitchen and Bath. It is also Premium Plus grade. He said only water based paint can contain anti-molding chemicals while oil based paint cannot. I am confused which type of paint I should used and hope the experienced or experts can give me some help. Also how should I properly prepare the ceiling for painting? How should I deal with cracks and holes on the ceiling? Would the Behr Primer and Sealer good for that purpose? Which type of paint should I used for the walls?