Step 1: Remove everything from the fireplace and wipe with a rag.
Step 2: Now that you’ve removed all soot and debris, you can use warm-water, bleach and Trisodium Phosphate (TSP) solution to deep-clean your fireplace walls and floor.
Step 3: Mix 6 tablespoons of TSP cleaner, 1 cup of bleach, and 1 gallon of warm water into a plastic bucket.
Step 4: Wearing your gloves, dip your nylon brush into the bucket, and then use the solution to scrub the walls and floor of your fireplace until they’re clean. (Old fireplaces may contain stains you can’t remove.)
Step 5: Rinse the floor and walls with clean water and towel-dry.
Step 6: Replace your grate and and irons. You’re now ready for the winter!