Steps:1. Cover surrounding floor with drop cloth. Pull out fireplace surround and wood grate to give you more working room.
2. Put on the dust mask, safety goggles and gloves and use the wire brush to scrub down the base and sides of the fireplace (figure A). Sweep away debris using dustpan and hand broom. This will remove the first layer of soot and ash and give you a better look at the mortar joints.
3. Take a flat head screwdriver and probe into the joints, scraping out any loose mortar (figure B). Use a small paintbrush to clean out joints. Check all the joints, in the floor and sides of the fireplace.
4. Vacuum up fine dust particles to clean area.
5. Using a flat trowel as a tray, take a scoop of mortar and place it on the trowel. Chop down mortar using tuck-pointing trowel. Place the edge of the flat trowel up against mortar joint and fill joint with mortar using tuck-pointing trowel (figure C). Use tip of tuck pointing trowel to smooth everything out.
6. Allow mortar to dry for at least an hour, then remove excess mortar with small rectangular trowel. Sweep away debris and you're done.