Whether the surface to "breathe", if a water based paint be applied over old oil?
Vapor-permeable coating called "breathing". From the point of view of ecological climate of the home is the best option for staining wood, concrete, brick facades, and walls and ceilings in the interior. The property of water vapor is lost, if the permeable coating is applied on top of the old a totally reflecting coating (oil paint, alkyd enamel, alkyd, or urethane varnish, organorazbavlyaemye impregnation with varnish coating, waterproofing). If you want to restore the ability of a surface to breathe, the old coating must be removed completely.