How to clean soot off fireplace brick, and when the soot means a problem.

Soot on fireplace brick is common, and most of it can be cleaned. This guide covers how to do it without damaging the brick, what the experts disagree on, and when the soot is a sign of something that needs fixing.

Our sources are the Brick Industry Association’s guide to cleaning brickwork, the NFPA, the CDC, the EPA and the Chimney Safety Institute of America, along with a masonry cleaner maker and a Michigan hearth store. Where they disagree, we say so. We are a restoration company that cleans soot after fires, so we have tried to be clear about what you can do yourself.

Before you start

• Make sure it is cold. No warm ashes or embers. The EPA recommends putting ashes in a covered metal container stored outdoors on a surface that cannot burn.
• Protect the room. Lay a drop cloth over the floor in front of the hearth, as FireSide Hearth & Home, a Michigan hearth store, suggests. Prosoco notes that dry soot gets into the air easily while you work.
• Protect yourself. Wear gloves and eye protection, and open a window for ventilation, especially if you use a strong cleaner.
• Look at the brick first. Prosoco, which makes masonry cleaners, says brick that is flaking or crumbling, mortar that is breaking down, painted or sealed surfaces, and soft older brick need special treatment, and the wrong method can damage them for good.
• Test a hidden spot. The Brick Industry Association says some cleaners react with minerals in certain brick and can cause or worsen stains, so always try a small, out-of-sight area first and judge it once it is dry.

How to clean soot off fireplace brick, step by step

1. Start dry

Brush and vacuum the brick gently to remove loose soot. Prosoco explains that soot settles into the pores of brick and mortar, and adding water too early dissolves it and spreads it deeper. Getting the loose soot off first means less to smear later.

2. Try soap and water

For light soot, FireSide says soap and water with a scrub brush will do it, though it takes some elbow grease. Use a stiff bristle brush, not a wire one. The Brick Industry Association warns that wire brushes can damage the brick surface, so avoid wire brushes and drill-mounted wire wheels.

3. For smoke stains that remain, use scouring powder

The Brick Industry Association’s advice for smoke stains is to scrub with scouring powder, particularly one containing bleach, and a stiff bristle brush. It also says ready-made masonry cleaners for smoke stains are generally safer, easier to control and more consistent than homemade mixes. Follow the label.

The CDC warns never to mix bleach with ammonia or any other cleaner.

4. For heavy buildup, TSP or a masonry cleaner

FireSide suggests trisodium phosphate (TSP) for heavy soot: a quarter to a half cup in about two gallons of water, scrubbed on with a sponge or brush. It stresses gloves, goggles and ventilation. The Red Cross calls TSP caustic.

5. Rinse carefully and let it dry

Work in small sections. Prosoco says rinsing should remove the lifted residue without flooding the surface, because extra water moves the remaining soot around. Let the brick dry fully before judging the result.

What to avoid, and where sources disagree

• Strong acids. The Brick Industry Association says not to use unbuffered muriatic (hydrochloric) acid, which can stain brick and damage mortar, and notes that light-colored brick is more prone to “acid burn”.
• Vinegar. Google’s AI summary suggests a vinegar and water spray. Prosoco says acids can etch brick and weaken mortar. If you try vinegar, test it first, and skip it on light-colored or old, soft brick.
• Household cleaners. The Brick Industry Association says kitchen cleansers, bleach and other household products can remove many stains. Prosoco, which sells masonry cleaners, says household soaps leave residue in the brick that attracts more soot. Rinse well whatever you use.
• Wire brushes. Popular videos use a wire wheel on a drill. The Brick Industry Association says wire brushes can damage brick.

When the soot means a problem

Some darkening is normal. Prosoco explains that every fire releases carbon particles that rise, cool and settle back on the surrounding brick, concentrating around the firebox opening over time. But soot that spreads onto the mantel or the wall, or smoke you can see or smell in the room, is a sign to look closer.

• Smoke in the room is a warning sign. The EPA says properly installed, correctly used wood-burning appliances should make very little smoke, and if you regularly see or smell smoke you may have a problem. (The EPA’s Burn Wise program ended in 2025 and its site is now kept as a historic record, but the advice still stands.)
• Burn the right wood. The EPA says to burn only dry, split wood seasoned for at least six months, to build hot fires rather than letting them smolder, and never to burn trash, cardboard, painted or treated wood, or plywood.
• Have the chimney checked every year. The NFPA says chimneys should be inspected and cleaned each year before the season. The CDC says a chimney blocked by debris can cause carbon monoxide to build up inside your home. The Chimney Safety Institute of America says an annual inspection by a qualified professional helps prevent both carbon monoxide intrusion and chimney fires.
• Have working carbon monoxide alarms. The CDC recommends battery or battery-backup carbon monoxide alarms near every sleeping area. It lists headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion as the most common symptoms of poisoning.

Winter is when this matters most. NFPA figures for 2020 to 2024 show nearly half of home heating fires happen from December through February, and that fires involving fireplaces or chimneys caused about a fifth of the property damage from heating fires.

After a chimney fire

The Chimney Safety Institute of America says not to use the chimney until a qualified chimney professional has swept and inspected it, because the damage often cannot be seen from above or below. It also says most chimney fire damage is a covered loss under homeowners insurance. Ask the sweep to photograph the damage before sweeping, and get a written repair estimate for your adjuster. If smoke reached the rest of the house, our guides on cleaning soot off walls and ceilings and getting rid of smoke smell pick up from there.

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