Chimney Cleaning Cost Calculator

A cleaning costs what the buildup makes it cost. Start from your base rate, pick how dirty the flue is, and see the number move — a lightly used chimney cleans fast, a glazed one drags.

Planning estimate: this is a planning estimate from the numbers you enter — not a bid or a contract. Chimney and masonry price depends on access and scaffolding, the extent of the damage, materials, chimney height, roof pitch, permits and local labor. Get itemized written quotes from a CSIA-certified sweep and a licensed, insured mason before you commit.

1 Enter your numbers

$
What the sweep charges for a normal, lightly-used flue.
How much soot and creosote the sweep expects to find.
$
Roof-access or show-up fee, if billed separately.
A cushion for surprises — enter as a fraction, so 0.10 means 10%.
Your result
Estimated total$261
Base clean$150
Condition (Moderate buildup)×1.25
Access$50

Cleaning cost tracks how much soot and creosote there is — a lightly used flue cleans fast, a heavily glazed one takes longer. At Moderate buildup (×1.25) this is about $261. The multipliers are labeled planning typicals you can adjust.

The word “cleaning” hides a two-to-one price range, because the work is set by what is stuck to the flue, not by the flue itself. A chimney lit a handful of evenings a winter carries a thin, powdery soot that a rotary brush clears in one pass. A daily-burned stove — especially one fed unseasoned wood or damped down for long smoky smolders — glazes the flue with hard buildup that takes more passes, more time and sometimes a different tool. This calculator models that with a plain condition multiplier you can override: light leaves the base rate alone, moderate lifts it about a quarter, heavy about half. The condition itself is the sweep’s call once the camera is up the flue — you are pricing the scenarios, not diagnosing the chimney.

Formula

total = (base rate × condition multiplier + trip / access) × (1 + contingency)

Condition multipliers are LABELED planning typicals: light 1.00×, moderate 1.25×, heavy 1.50× — adjust them to match what your sweep quotes.

Worked example

Take a wood-burner used most nights: base rate $155, the sweep flags it heavy (1.50×), a $48 access fee, 10% cushion:

(155 × 1.50 + 48) × 1.10 = (232.50 + 48) × 1.10 = 280.50 × 1.10 = $309

Drop the same flue to light and it is (155 + 48) × 1.10 ≈ $223 — the buildup, not the chimney, is the $86 difference.

Before you book: what “dirty” really means

  • Powder vs glaze. Dry, black powder is light-to-moderate. Shiny, tar-like glaze is Stage 3 creosote — brushing barely marks it. Price that as creosote removal, not a cleaning.
  • Burn habits set the buildup. Seasoned wood, hot fires and an insulated liner keep a flue clean; wet wood and long damped-down smolders coat it fast.
  • Gas is not exempt. A gas fireplace still needs the flue and vent checked for debris, nests and corrosion — less soot, same look-over.
  • One visit, two flues. If the furnace shares the chimney, expect a second, usually discounted, line rather than a doubled base rate.

Reference table

Labeled planning multipliers — adjust to your sweep’s quote. The condition is judged with a light or camera up the flue.

Flue conditionCost multiplier
Light use1.00×
Moderate buildup1.25×
Heavy / glazed1.50×

Frequently asked questions

What is the difference between cleaning and a routine sweep?
A routine sweep is the flat, lightly-used case; a cleaning prices in how much buildup there is. This tool scales a base rate by a light / moderate / heavy condition multiplier. For the plain flat-rate job see the sweep-cost tool.
Why does the flue condition change the price so much?
Because it changes the labor. Light soot is one brush pass; heavy glaze needs repeated passes, sometimes rotary heads or chemical loosening, and more careful vacuuming and masking. More time on the roof is more money, so the multiplier tracks the effort.
Can I clean the chimney myself?
You can brush a straightforward, lightly-used flue with a rod-and-brush kit, but you lose the trained eye that spots a cracked tile, a bad crown or a fire hazard. For anything glazed, offset or tall, hire a CSIA-certified sweep — the inspection is half the value.
How do I know if my flue is “heavy”?
You usually cannot from the hearth — it takes a light and a mirror or a camera up the flue. A strong campfire smell when cold, poor draft, or a flue lined with shiny black tar all point to heavy buildup. The sweep confirms it; the creosote-stages reference explains what they are looking at.
Does a rarely-used fireplace still need cleaning?
Have it checked yearly even if you barely light it — animals nest, mortar sheds and moisture corrodes whether or not you burn. If the check finds little buildup, it prices as a light cleaning or a plain sweep.