How to Clean the Exterior Masonry Wall of a Fireplace

The soot buildup on the face of your stone fireplace detracts from its beauty and poses a fire hazard. You can restore the masonry by cleaning it with acid wash. The process involves a moderate amount of skill and some basic materials.

Things You'll Need

• 1/2 gal. hydrochloric acid
• 5 gal. water
• Small wire brush
• Clean, dry rags
• 2 5-gal. buckets
• Safety glasses
• Dropcloths
• Rubber gloves

Instructions

1. Lay out dropcloths to prevent acid from coming into contact with your flooring or furniture. Work only on the dropcloths.

2. Pour 2 gal. of water into a 5-gal. bucket. Pour 1/2 gal. of hydrochloric acid into the water and mix them by swirling the liquid in the bucket.

3. Pour 3 gal. of water into another 5-gal. bucket and toss in a couple of clean rags. Keep this bucket of rinse water on hand to wipe away the acid as you go. Replace the rinse water as necessary.

4. Apply the acid wash to the stonework with a rag; keep this rag out of the rinse bucket. Soak the masonry and remove any debris with your wire brush. Start at the top of the fireplace and work your way to the bottom.

5. Wipe away any soot residue and acid wash with a rag from your rinse bucket. Clean a small section of stonework with the acid wash and immediately rinse it.

6. Allow your fireplace to remain unused for at least 24 hours after cleaning.

Tips & Warnings

• Dispose of used acid wash according to directions on the packaging.

• Wear safety glasses and rubber gloves when working with acid or any other chemical.

References

• Fireplace Maintenance