Trying save time and money I was asked to just tile right over the old tile which was still very solidly attached to the fireplace. Tiling over tile is typically an acceptable practice, assuming that the underlying tile is in good shape and you have a flat, smooth surface to lay new tile over. It’s also important to consider the height change if you decide to tile over an old tile floor, for example.
Thankfully, the mantle and fire box were in decent condition needing only a fresh coat of paint. The firebox has been boarded up for years, making it a home for birds and other wildlife. It will get a good cleaning and painted black. Then, with a little maintenece it could be a working and functional fireplace again.
I would be laying a 4″ tumbled slate tile that was just full of different colors that would provide plenty of interest to this fireplace that is the centerpiece of this living room. The tile took less than a day to lay and then a few hours the next day to grout. It’s a quick project that changes the vibe of the entire room.