It depends. If the decorative finish is “flat”, i.e. devoid of physical texture, you can consider it equivalent to any other painted surface. We do not use materials that will resist the adhesion of additional coats of paint and thus there is no reason to hesitate. Of course, once painted over, the decorative finish is lost forever, but that’s obvious. In certain finish types, special waxes may be used to provide a sealed finish. In these cases, consult your painting professional before overpainting, as the effect of wax may be to impede adhesion. In this case, wax removal via the use of naphtha may be required.
Physically textured surfaces are another story. Because of the raised surface due to the application of a texture product, any overpainting will provide a new fresh coat of color, however you should expect that the surface relief due to the texture will be apparent and show through the new paint. This is sometimes a favored feature and can create a beautiful effect. But if this is not desired and a return to a flat surface is desired, the texture will need to be dealt with, either by sanding, skim coating, or possibly replacement of the surface itself (e.g. new Sheetrock).
Upon project completion, we do not deem the relationship with you over or finished. Rather, we see the project we performed for you as merely the beginning of hopefully a long, strong, fruitful association.
We are available to you post-project and ongoing to address problems and issues and ask that you never hesitate to call with any questions. If needed, we strive to help provide new solutions for you as required on into the future. Your ongoing satisfaction is our goal and we seek to be a resource as needed.