How do you treat a roughcast wall be for painting?

Before painting a roughcast wall, clean the surface to remove dirt, dust, and loose material; a power washer can be effective for this. Next, repair any cracks or damaged areas with a suitable filler and allow it to dry completely. Prime the wall with a masonry primer to enhance paint adhesion, then choose an appropriate exterior paint that can withstand the texture and weather conditions. Finally, apply the paint using a roller or spray for even coverage, ensuring you work it into the texture of the roughcast.