This is my fireplace. We've repainted everything so far and refinished the floors, but we are stumped about what to do with a painted brick fireplace. It's so tightly situated on the wall and sandwiched between 2 doorways. This makes it difficult to put any kind of mantle over it, without intruding on the existing door frames. Until now, every article about refacing with tile has called for cement board to be screwed into the bricks. The thickness of these boards would not work with the existing mantle, so I have been looking for another solution. Looks like Joe Ferrante of This Old House has the answer with this how to tile over brick.
Cover the hearth with a drop cloth and remove the mantel and anything else that's attached to the brick. Go over the entire area with a wire brush to dislodge any loose mortar, then scrub off the soot with a rag soaked in white vinegar. Let the bricks dry for a day or two, then mix up a batch of white, latex-modified thinset cement to the consistency of mayonnaise. Spread the thinset over the brick with a flat, straight—not notched—trowel and force it into all the grout joints. If the joints are still visible after the first coat cures, skim on a second coat to fill in any depressions. If you do it right, you’ll end up with a surface that’s as flat as backerboard but without any seams. The next day, lay down a new bed of latex-modified thinset combed out with a notched trowel, and set your tiles into that. Don’t use mastic; it can’t take the heat. more here...
