Tile is not recommended for applications that will exceed 175 f 80 c so it s not an option for the firebox.
Can you tile over tile fireplace.
Smooth the tile down with your hand.
The peel and stick tiles have a little extra space on one side so you can overlap them slightly so there are no gaps.
The row of tiles directly above the firebox is visually the most important so it should be absolutely straight.
Then take that piece and hold it up to the previous piece you cut to make sure it is the same width length whichever is applicable.
One strategy is to clean the marble with tsp and water then sand it with coarse sandpaper to etch it.
You can tile directly over your current marble fireplace surround.
Nowadays it is quite possible to tile over the old tile and avoid the time and money of cleanup and backerboard installation.
The average do it yourself homeowner can cover their old tile fireplace surround with new tile in one to two days depending on the size and scope of the project.
Then if you use the proper mastic the tiles should stick.
How to tile with before and after pictures of a fireplace surround makeover.
The board also prevents the tiles from slipping before the adhesive cures.
If you want to tile over a marble fireplace you have to address the problem of tile adhesion.
Each time you cut a piece of tile take it over to fireplace and hold it up to make sure it fits.
Nail a straight 1x board horizontally across the fireplace in line with the top of the firebox and use its top edge as a shelf as you set the tiles.
The firebox is where the actual fire will be and it must be lined with the appropriate materials that will meet building codes.