Chimney Sweep
Flue Cleaning Built on Four Generations of Minnesota Chimneys
A sweep removes creosote and soot from the flue liner, smoke shelf and smoke chamber, and it is the only reliable way to find out how a chimney is actually burning. NFPA 211 calls for an annual inspection of every solid-fuel appliance, and in a Minnesota winter a wood stove run on unseasoned birch can lay down a glazed third-degree deposit in a single season. We work top-down with rotary heads and a HEPA vacuum, then hand over photographs of the liner rather than an assurance that it looked fine.
How the work is approached
What Sweeping Actually Does
A chimney sweep clears the flue so combustion gases vent properly and deposits don't ignite. Creosote builds up as wood smoke cools against the liner, and soot accumulates from incomplete combustion. Both restrict airflow and both burn at temperatures that crack tile.
Minnesota Heating Season and When to Book
A continental climate with long, dry, very cold winters and warm humid summers. Heating season runs from early October into late April, and the first hard freeze usually lands in the second week of October. That first freeze triggers the booking rush.
How We Contain the Mess
Sweeping generates soot and dust, but a HEPA vacuum captures it before it enters the room. We seal the firebox opening with a fitted shroud, tape drop cloths across the hearth, and run negative pressure throughout the job. The vacuum pulls air into the flue rather than pushing debris out.
| Typical price | $189 to $349 |
|---|---|
| Price basis | One straight masonry flue up to 25 feet, accessible from a walkable roof, no glaze removal |
| Billing unit | Per flue |
| Permit | Not marked as required |
| Typical duration | 1.5 hours |
| Typical booking lead | 10 days |
Creosote Stages and What Each Costs to Remove
Creosote forms in three stages. First-degree creosote is flaky and brown, brushes off easily, and adds no time to a standard sweep. Second-degree creosote is black, shiny, and harder, requiring a stiffer brush and a second pass. Third-degree creosote is glazed, tar-like, and often ignited at least once already.
Glaze doesn't brush off. It requires a rotary whip or chemical treatment, followed by a second visit once the glaze breaks down. That's why glazed flues cost more: the job doubles. Glaze forms when flue gases cool below 250 degrees before they exit, which happens with wet wood, restricted air, or an oversized flue.
Minnesota winters tempt people to burn whatever splits, and wet birch glazes faster than any other common cordwood. If you see a shiny black coating when you shine a light up the flue, call before you burn again. Glaze ignites above 1,000 degrees and tile cracks at 1,200.
NFPA 211 and Inspection Frequency
NFPA 211 calls for an annual inspection of every solid-fuel appliance. That's chimneys, wood stoves, and fireplace inserts. The standard doesn't specify sweeping frequency because deposit rate varies with fuel, burn habits, and flue temperature. Inspection determines whether sweeping is needed.
A household that burns two cords of seasoned oak per winter might go two years between sweeps. A household burning unseasoned mixed hardwoods might need sweeping twice in one season. The only way to know is to look, which is why the inspection comes first.
We're CSIA certified and we follow NFPA 211 for every job. The inspection is part of the sweep: we document the before condition, clear the flue, then document the after condition and flag anything that needs repair. You get the report in writing, with photographs, the same day.
Permits and Code Compliance
Minnesota adopts the International Mechanical Code through the Minnesota Mechanical Code, Minnesota Rules chapter 1346. Liner installations and structural chimney rebuilds are permitted work almost everywhere in the metro; sweeps and inspections are not. Sweeping is maintenance, not construction, so no permit is required and no inspection follows.
If we find damage that requires a liner or a rebuild, that work does require a permit. The configured typical permit fee is $110. The configured permit turnaround is 5 days. The configured permit process names The city building or mechanical inspections department for the municipality as its permitting authority. The configured permit process requires an inspection.
We pull permits when the job calls for one and we schedule the inspection before we leave the site. Code compliance isn't optional, and an unpermitted liner replacement can stall a home sale or void insurance after a fire.
Freeze-Thaw Cycles and Flue Integrity
The local climate profile records 45 freeze-thaw cycles. Water enters a crack in the crown or a failed mortar joint, freezes overnight, expands, and widens the crack. By March the crack is a gap, and by April the liner is exposed to rain.
The local climate profile lists freeze-thaw spalling as a hazard. Spalling is the flaking or crumbling of masonry surfaces after repeated freeze-thaw cycles. Once the surface breaks, water penetrates deeper and the damage accelerates. A spalled chimney crown sheds chunks onto the roof; a spalled liner lets combustion gases into the house.
We inspect the crown, the cap, and the visible portions of the liner during every sweep. If we see spalling or open joints, we'll photograph it and give you a repair estimate before we leave. Catching it early means a $400 crown seal instead of a $3,200 crown rebuild.
Frequently asked questions
How often does a chimney actually need sweeping?
NFPA 211 requires annual inspection, but sweeping frequency depends on how much you burn and what you burn. A household burning two cords of seasoned hardwood per winter might sweep every other year. A household burning wet wood or softer species like pine might need sweeping twice in one season. The inspection tells you whether enough creosote has accumulated to justify a sweep. We measure deposit thickness and photograph the liner so you see exactly what we see.
Will sweeping make a mess inside the house?
No, if the job is done correctly. We seal the firebox opening with a fitted shroud and run a HEPA vacuum at negative pressure throughout the sweep. Most debris is captured before it enters the room. You'll find a thin layer of dust on surfaces within a few feet of the hearth, but nothing beyond that. Move furniture back three feet from the fireplace and clear the mantel before we arrive. We handle the rest.
What is glazed creosote and why does it cost more to remove?
Glazed creosote is a shiny, tar-like third-degree deposit that forms when flue gases cool too much before exiting. It doesn't brush off. Removing it requires a rotary whip or chemical treatment, then a second visit days later once the glaze breaks down. That doubles the labor, which is why it costs more. Glaze forms from burning wet wood, restricted airflow, or an oversized flue. It ignites above 1,000 degrees and can crack tile.
Can you sweep a chimney in winter?
Yes. We sweep year-round, including January and February. Cold weather doesn't prevent sweeping; ice on the roof and snow covering the flashing can slow access, but we work through it. In fact, mid-winter sweeps often catch problems before they turn into chimney fires. If you're burning regularly and notice poor draft or smoke spillage, don't wait until spring. We'll get on the roof regardless of temperature and clear the flue the same day.
Do I need to be home during the sweep?
Yes, because we need access to both the roof and the interior firebox. We seal the firebox from inside, run the vacuum from inside, and hand-brush the smoke chamber from below. If you can't be home, you can arrange for someone else to let us in and stay until we finish. The job typically takes 60 to 90 minutes for a single flue. We'll call when we're 15 minutes out.
What do you look for during the inspection?
We check the crown for cracks, the cap for rust or blockage, the flue for creosote thickness and type, the liner for cracks or spalling, the smoke chamber for buildup, the damper for function, and the firebox for damage. We photograph anything that needs attention and include those images in the written report. The inspection is part of every sweep, not an upsell. If the chimney is sound and the flue is clean, the report will say so.
How much creosote buildup is too much?
NFPA 211 recommends sweeping when creosote accumulates to one-eighth inch or more. At that thickness, the deposit restricts airflow and presents a real ignition risk. We measure thickness with a gauge and document it in the report. First-degree creosote at one-eighth inch brushes off quickly. Third-degree glaze at any thickness is a problem and gets flagged immediately. If you see shiny black coating when you shine a light up the flue, call before you burn again.
Can a dirty chimney cause carbon monoxide problems?
Yes. A blocked or restricted flue prevents combustion gases from venting, and those gases include carbon monoxide. Creosote buildup, bird nests, or a closed damper can all create enough restriction to cause spillage into the living space. That's why NFPA 211 calls for annual inspection. If you have a CO detector alarming near the fireplace or you smell smoke when the fire is burning, stop using the fireplace and call immediately. We'll clear the obstruction the same day.
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