How to Change the Color of Rock Siding

Put on rubber gloves.

Wash the rock siding with muriatic etching solution and a rag. Muriatic etching solutions get rid of grime, and they also condition stone for better primer adhesion.

Apply concrete patching compound to any cracks in your rock siding. Use a putty knife to smooth out the patching compound. Paint won't hide imperfections, and cracks can get worse over time. Before you apply paint, you need to address this important maintenance issue. Wait for the patching compound to dry before continuing.

Protect the building's trim with painter's tape.

Spray the surface with masonry primer and an airless spray gun. Masonry primer is available at most hardware stores. It costs a few dollars more per gallon, but it works better on rock than general purpose primer. Wait 24 hours for the primer to cure. Even if the primer appears dry before 24 hours, it may not be fully cured.

Paint the rock siding with exterior elastomeric paint and a spray gun. Elastomeric paint is formulated to fill small surface imperfections for better coverage of rough, rocky surfaces. Elastomeric paint covers most rock siding in just one coat, while exterior latex paints would take two or three coats. Let the elastomeric paint dry for 24 hours before removing the painter's tape.