Clean the stone or brick fireplace with a damp cloth. Use the cloth to remove soot and dirt from the surface of the fireplace. Let the fireplace dry completely. Place drop cloths beneath the fireplace to protect your floor from paint.
Pour a small amount of oil-based primer into a tray. Use a high-nap roller and a paintbrush to apply the oil based primer to the outside area of the fireplace. It is especially important to cover sooty areas of the fireplace, or areas that may bleed through the paint. Let the primer dry per manufacturer directions.
Pour semi-gloss latex paint into a painting try. Use a high-nap roller and a paintbrush to cover the stone or brick fireplace with paint. The paint may soak into the stones or brick so you will probably need to apply two or three coats of paint.
Let the paint dry per manufacturer directions. Remove the drop cloths from the floor.