Smoke damage on walls and ceilings: how to fix it

Why you cannot just wipe it

Soot is made of very fine particles, often bound with oily residue. Wiping it with a wet cloth pushes that residue into the paint and spreads it, leaving a grey smear that is harder to remove than the original mark. On flat paint, wallpaper and textured ceilings the damage can become permanent.

The order matters: dry removal first, then wet cleaning, then sealing.

Identify what you are dealing with

Dry, powdery soot from a fast-burning fire of paper or wood. Brushes off the finger. The easiest to clean.

Oily, smeary soot from smouldering fires and burnt plastics, rubber or synthetic fabrics. Sticky, with a sharp smell.

Protein residue from burnt food. Almost invisible, a yellowish film that discolours finishes and smells strongly.

Furnace soot from a puff-back. A fine black film through the whole house, heaviest around vents.

Candle and fireplace soot. Dark lines along ceiling edges, around vents and above candles, built up over time.

Step by step for light to moderate soot

1. Ventilate and turn off the furnace fan so that soot is not circulated.
2. Protect floors and furniture with drop sheets.
3. Wear gloves, eye protection and a dust mask.
4. Vacuum loose soot with a HEPA-filtered vacuum, holding the nozzle just off the surface. Do not use a brush attachment, which grinds it in.
5. Use a dry cleaning sponge, made for soot, in straight overlapping strokes from the ceiling down. Do not scrub. Slice off the dirty surface as it loads up.
6. Wash with a degreasing detergent in warm water, changing the water often. Work in small sections.
7. Rinse with clean water and dry.
8. Assess. Any remaining stain or odour needs sealing.

Test every product in a hidden spot first.

Ceilings need extra care

Smoke rises, so ceilings carry the heaviest deposit. Textured and stippled ceilings cannot be scrubbed and are easily damaged by water. They are usually vacuumed, dry-sponged where possible and then sealed and repainted. In an older house, a textured ceiling may contain asbestos, so it should be tested before it is sanded, scraped or removed.

Sealing and repainting

Ordinary primer and paint let smoke stains and odour bleed back through within weeks. Use a stain-blocking, odour-sealing primer over the cleaned surface, then repaint. Paint the whole wall or ceiling so that the finish is even.

When to stop and call a professional

• The soot is oily and smears on the first test
• More than a room or two is affected
• The residue came from an actual fire, not just a cooking incident
• The smell remains after cleaning
• The surfaces are wallpaper, unsealed wood or delicate finishes
• There is soot around vents throughout the house, which points to the ductwork

Professional cleaning matches the method to the residue, cleans the ducts and deals with odour inside cavities that washing cannot reach.

Insurance

Smoke damage from a fire in your home is normally part of a fire claim. Photograph the affected rooms before you clean, and ask your adjuster before starting work that could affect the claim.

Mistakes that make it worse

• Starting with a wet cloth. It smears the residue and drives it into the paint.
• Scrubbing in circles. Use straight, overlapping strokes so that soot is lifted, not ground in.
• Using the furnace fan or ceiling fans. They move soot to clean rooms.
• Painting to save time. Without cleaning and sealing, the stain and the smell return.
• Using scented cleaners. They add a smell on top and can react with the residue.
• Leaving it for weeks. Residue becomes harder to remove the longer it sits and can permanently discolour plastics and finishes.

More: smoke damage and odour removal.