This will stop the stones and cement from absorbing the chemicals used to clean the stones. (i quit smoking, and started cleaning), prepare the area and have towels ready, the soot will start dripping off right away, so you don't want the dripping dirty cleaner to get on anything nearby.
Once you have removed all you can, you should wet the stones as much as possible.
How to clean stone fireplace rock. Depending on the type of rock, a simple soapy water wash may not penetrate the porous surface of the stone. Lay a plastic tarp on the floor to protect it from the cleaner, and duct tape the edges to hold it down and prevent leaks. You may notice that this may not have worked very effectively on the grouting.
Here’s how to clean a stone fireplace. Clean your stone fireplace with oxygen bleach. Stone fireplaces accumulate soot just like any other fireplace surface.
Wear rubber gloves and eye protection at all times. This mixture is toxic though so you should make sure that you have a proper mask and gloves and that all your windows open for proper ventilations. If you are cleaning an area outdoors, then this job is easy, but if you are inside you need to be a bit more careful.
First, to clean the stone, use shaving foam, as this is basically just regular soap but much easier to clean off. Mix a solution of tsp (trisodium phosphate) in warm water in the bucket according to package directions. You can use a sponge to do this on the vertical stones.
If all else fails, mix a gallon of water with half a cup of trisodium phosphate and scrub your stone fireplace clean. You may have to rinse and repeat if the soot has been there for a long time. Once you have let it sit, it is time to actually remove the build up from your brick or stone.
However, building over the top may not be possible since it appears that the existing stone is butted up next to the windows on each side. You can remove the stone down to the wood studded chase as coastroad hearth & patio suggested or build over it like mark suggested. Sweep of vacuum up as much dust as possible from outside the fireplace.
If the stones on your fireplace aren't sealed, you will have to use a hard bristle brush to remove any debris. Mix a cup of ammonia with a gallon of water. Rock fireplaces add a majestic, natural feel to a room, but owning a rock fireplace comes with its own share of unique maintenance problems, not least of which is cleaning the accumulated soot and grime.
Fill a trigger sprayer and neutralize the entire fireplace with. Steps to clean the stone: How to use vinegar to clean rock fireplaces | hunker | rock fireplaces, stone fireplace, painted stone fireplace.
The stone, however, is a porous surface that requires bit of a deep cleaning to entirely remove the soot residue. After donning gloves and a dust mask, dunk a clean scrub brush into the soap solution, then scrub down the fireplace surround from top to bottom to loosen trapped dirt and grit in the stone and. Using a toothbrush that you do not plan on using again, dip it in vinegar and scrub the grouting.
And don't forget to seal the brick after you clean and dry it. For outdoor cleaning, simply take your hose or a bucket of water to rinse the area and flush off all of that soot, tar and dirt.