No, it is not recommended to paint latex over oil-based paint on walls without proper preparation. Oil-based paint creates a slick surface that does not allow latex paint to adhere well, leading to peeling and flaking over time. To ensure successful adhesion, the surface must be thoroughly cleaned, sanded, and primed with a bonding primer specifically designed to promote adhesion between oil-based and latex paints. This will create a suitable base for the latex paint to adhere to, providing a durable and long-lasting finish. Failure to properly prepare the surface may result in paint failure, requiring costly repairs and rework. It is crucial to follow the correct preparation steps to achieve a professional and lasting paint job when switching from oil-based to latex paint on walls.

The risk is that some paint will stick well and some won’t. The result is a wall that is easily damaged and paint that will chip off or possible peel sometime in the future. If you use a good oil based primer first the paint will adhere properly.