How to Clean Soot Off of Walls

Soot being wiped off from wall with sponge above fireplace

The Spruce / Sanja Kostic

Project Overview
  • Working Time: 20 mins - 1 hr, 20 mins
  • Total Time: 30 mins - 1 hr, 30 mins
  • Skill Level: Beginner
  • Estimated Cost: $20

Contrary to popular opinion, it doesn't take a large fire in your home to leave soot marks on the walls. Even a quick flash fire on the kitchen stove, an improperly vented fireplace, or a burning candle can cause visible soot to accumulate on walls and ceilings.

Soot is not only unsightly—it can be dangerous, too. Soot is the result of incomplete combustion of organic materials and appears as a fine black powder that is sticky and clings to surfaces like walls, chimney interiors, and exhaust pipes. Excessive accumulation of soot is not only unsightly but can actually result in spontaneous combustion, making it incredibly important to remove.

Soot can also be detrimental to your respiratory system if the particulates are inhaled, so it's important to wear protective gear like safety glasses, gloves, and a mask when cleaning it away from surfaces. With a little time and attention, soot can be successfully removed from most surfaces.

How Often to Clean Soot Off Walls

As a general rule of thumb, it's a good idea to clean soot off your walls the moment you notice its presence. It's important not to let the soot build up, which can cause more of an issue (and be more difficult to clean) in the long run.

What You'll Need

Equipment / Tools

  • Rubber gloves
  • Safety glasses
  • Protective mask
  • Protective clothes
  • Drop cloths
  • Sturdy step stool or ladder
  • Buckets
  • Cellulose sponge
  • Measuring cups and spoons
  • Microfiber cloths
  • Vacuum
  • Utility knife

Materials

  • Dry cleaning or soot sponge
  • Trisodium phosphate (TSP) or TSP-PE (phosphate-free)
  • Dishwashing liquid with a degreaser

Instructions

How to Clean Soot Off of Walls

Materials and tools to remove soot from walls

The Spruce / Sanja Kostic

  1. Wear Protective Gear

    Before you begin cleaning, put on a pair of safety glasses and a mask to protect yourself from the harmful carbon in soot, rubber gloves to protect your hands from harsh chemicals, and old clothing or protective coveralls to prevent stains on your clothes.

    Green rubber gloves being put on for cleaning soot

    The Spruce / Sanja Kostic

  2. Empty the Room or Cover Furniture and Carpets

    As you remove soot from walls and ceilings, some of the particles will become airborne and will settle on upholstered furniture or carpets that can't be easily cleaned. If possible, empty the room of furniture, accessories, and floor coverings. If that is not possible, use tarps or drop cloths to protect everything you don't want to become soot-covered.

    Furniture being covered with white cloth before cleaning soot

    The Spruce / Sanja Kostic

  3. Ventilate the Room

    Open the windows to provide fresh air. Use circulating fans and turn on venting fans to help draw as many of the soot particulates out of the room.

    Once your cleaning is complete, you will need to change filters or clean the fans to remove soot particles.

    Windows being opened to ventilate space

    The Spruce / Sanja Kostic

  4. Vacuum the Walls

    If you have a vacuum with a hose and a dusting brush, you can use it to vacuum away some of the soot particles. This is a delicate operation because soot can smear.

    Start at the top of the wall and hold the vacuum brush at least one-half inch from the wall or ceiling surface to capture loose soot particles and dust. Do not make contact with the wall or smearing can occur.

    Warning

    No matter what method you use to remove soot stains, if they are located above your head, always use a sturdy step stool or ladder to reach them. Work slowly and move the ladder frequently to prevent falls.

    Vacuum hose removing soot particles from wall above fireplace

    The Spruce / Sanja Kostic

  5. Use a Dry Cleaning or Soot Sponge

    Specialty sponges for removing soot go by many names: soot sponge, dry cleaning sponge, chemical sponges. Made of vulcanized rubber, the sponge is extremely effective in grabbing and clinging onto soot to lift it from hard surfaces.

    The sponge will quickly become black as it absorbs the soot. Once the sponge surface is discolored, move to a clean side of the sponge. You can also use a utility knife to cut away a thin layer of the sponge to expose a fresh surface. Never attempt to clean the sponge with water or it will stop working.

    Start with the ceiling and move to the top of the wall and work your way down. Use straight, parallel strokes that overlap slightly. Remember to wipe, not scrub. You are working to grab the soot particles, not smear them around. The sponge may not remove all the staining caused by the soot but will get rid of the loose particulates. Dry cleaning should always be done before moving onto wet cleaning methods.

    Rubber sponge wiping soot-covered wall over fireplace

    The Spruce / Sanja Kostic

  6. Create a Wet Cleaning Solution

    If there is residual staining on the wall or ceiling, you will need to use a wet cleaning method.

    Trisodium phosphate (TSP) is regarded as the best product for removing soot. If it is not available in your area, there are similar soot removers that are phosphate-free (TSP-PF) You can also create a mixture of water and a dishwashing liquid that contains a degreaser.

    • Trisodium phosphate solution: In a bucket, mix two quarts of water with one-half cup powdered trisodium phosphate. Stir to mix well.
    • TSP-PF solution: Follow product label directions for mixing with water.
    • Degreasing dishwashing liquid solution: In a bucket, mix two quarts of water with two tablespoons dishwashing liquid. Stir to mix well.

    Warning

    Always wear protective gloves when working with TSP.

    Plastic bucket, rubber gloves and trisodium phosphate for wet cleaning solution

    The Spruce / Sanja Kostic

  7. Wash the Ceiling and Walls

    Use a regular cellulose cleaning sponge for cleaning. Dip it in the solution and wring so it is not dripping.

    Standing on a sturdy ladder, start at the ceiling or top of the wall and work your way down. Rinse and wring the sponge out frequently. Mix a fresh cleaning solution as the water turns black from the soot.

    Regular cellulose cleaning sponge wiping soot with wet solution from wall

    The Spruce / Sanja Kostic

  8. Rinse and Dry the Surfaces

    To make sure that the ceiling and walls are as clean as can be, dip a clean sponge in fresh water. Wring until just damp and wipe down the surfaces. Finish by drying the ceilings and walls with a lint-free microfiber cloth.

    Tip

    If you plan to paint the freshly cleaned walls, wait at least 24 hours before you begin to be sure that the walls are completely dry.

    Wall above fireplace being rinsed with lint-free microfiber cloth

    The Spruce / Sanja Kostic

  9. Remove Protective Materials and Vacuum

    Remove the drop cloths and tarps from the room and use a vacuum to clean the floors. Dispose of the vacuum bag carefully or empty the dust cup in a well-ventilated area to prevent the inhalation of the soot particles.

    Vacuum cleaning up wooden floors

    The Spruce / Sanja Kostic

Tips to Keep Soot of the Walls and Clean Longer

  • Keep candles away from the walls and away from drafts. Put them on coffee tables or dining tables instead.
  • Use unscented candles instead of scented candles which tend to produce more soot.
  • Trim the wicks of a new candle to 1/4 inch, as a candle that burns a steady flame rather than a flickering one produces less soot.
  • Make sure your fireplace is vented properly.