How to Build a Stone-Veneer Fireplace Surround

Let the grout cure until pressing it with a finger leaves a dent without breaking through the surface (about 60 minutes). Using the striking tool, carve the grout to the desired shape and depth. (You can use a store-bought striking tool, a chopstick, or the end of a 1x1 that's been rounded with sandpaper, depending on the size of the joints.) Achieve a classic look by carving a grout profile that sits below the face of the stones; for a rustic effect, like the one we used, shape the grout to sit flush with the stones (known as an overgrout technique), then go over the grout lines with a whisk broom to create a natural-looking finish. Let the grout cure for at least 48 hours before using the fireplace.