Sandstone fireplaces need regular cleaning. The supplies you need to keep your fireplace in top condition are stone cleanser, a soft scrub brush, a stiff scrub brush, warm water, natural soap, a paintbrush, a bucket, trisodium phosphate, towels, rubber gloves and a face mask. It takes about an hour to clean most fireplaces.
- Wash the stone
Wash the sandstone with stone cleanser and a soft scrub brush.
- Scrub sooty areas
Don rubber gloves and a face mask, then use a stiff, dry scrub brush on the fireplace's soot deposits. Treat stubborn soot stains with a solution of warm water and natural soap. Apply the cleanser with a paintbrush, wait 30 minutes and rinse with warm water. Soap residue gives sandstone a dull, discolored appearance, so rinse the fireplace thoroughly.
- Apply trisodium phosphate solution
Mix a gallon of warm water with 1/4 cup trisodium phosphate. Apply the solution with a soft scrub brush, and keep it on the stone for 15 minutes. Keep the cleanser away from metal, glass and house plants. Rinse with clean water and dry the sandstone with a towel.
- Dispose of the leftover trisodium phosphate solution
Pour leftover trisodium phosphate cleaner down a household drain. Do not remove your protective gloves and face mask until you dispose of the solution.