1Top of the flue
Cap
Keeps snow, rain and animals out of the flue, and its screen stops sparks before they land on a roof.
We check: fit, rust, a torn screen, nests.
Next: Crown
Boulder chimneys, swept and sound before the first snow.
Sweeps, inspections and masonry repair for homes across Boulder, from North Boulder to Table Mesa.
- reviews on Googleas of
- Office 7 AM to 9 PMEvery day
- Book onlineAny hour
- Boulder, COOur service area
Photo: Tyler Cipriani, CC BY-SA 4.0
Top to bottom, the six places a chimney fails.
Pick a part of a working chimney to see what we look at, and why Boulder weather is hard on it.
Start at the cap
From our Google Business Profile 
From our Google Business Profile 2The slab on top
Crown
Freeze and thaw work on it all winter: water in a hairline crack expands about 9% as it freezes.
We check: hairline cracks, spalling, gaps at the flue tile.
Next: Flashing
From our Google Business Profile 3At the roof line
Flashing
Seals the joint between chimney and roof, where snow piles up and downslope winds test every seam.
We check: lifted counterflashing, failed sealant, attic stains.
Next: Flue liner
From our Google Business Profile 4Inside the stack
Flue liner
Carries smoke and heat out. A cracked tile can let heat reach the framing and carbon monoxide reach the rooms.
We check: cracked or offset tiles, missing mortar, the right size.
Next: Smoke chamber
From our Google Business Profile 5Above the fireplace
Smoke chamber and damper
Creosote collects here first. The Chimney Safety Institute of America says sweep at 1/8 inch of buildup.
We check: glazed creosote, a damper that seals, open walls.
Next: Firebox
From our Google Business Profile 6Where the fire sits
Firebox
Firebrick and mortar take the direct flame. Small joint repairs here prevent large masonry repairs behind it.
We check: open joints, cracked firebrick, the hearth.
See all six
Six places, one visit.
An inspection covers all six, from the cap down to the firebox.
(983) 223-5376Or book online
Sweeping, inspection and repair, for the whole chimney.
From our Google Business Profile Book a sweepCreosote and soot come out of the flue, the smoke chamber and the firebox. A clean flue draws better and leaves a stray spark nothing to catch on.
- Flue, smoke shelf and damper
- Firebox and hearth
- Findings in plain words
From our Google Business Profile Book an inspectionA look at the whole system, cap to firebox. Worth doing every year, after a chimney fire, and when a house changes hands: NFPA 211 calls for a Level 2 inspection at a property sale.
- Crown, cap and flashing
- Flue, top to bottom
- Photos of problem spots
From our Google Business Profile Ask about a repairCrowns, caps, flashing, mortar joints and firebrick. Small repairs done early keep water and heat where they belong, before a freeze makes them bigger.
- Crowns and caps
- Spark arrestor screens
- Tuckpointing and flashing
From our Google Business Profile Book a cleaningFireboxes, smoke shelves and wood stoves cleaned and checked, so the first fire of the season starts clean and the damper opens and closes the way it should.
- Firebox and smoke shelf
- Wood stoves and stove pipe
- Damper operation
Boulder weather is hard on masonry.
Three things the Front Range does to chimneys, and why a small repair now saves a big one later.
01 / 03
9%. Freeze and thaw
Water expands about 9% when it freezes. Inside a cracked crown or an open mortar joint, each freeze pries the gap a little wider, and Boulder winters bring night after night below 32°F.
Source: Physics of ice
Photo: Perryjp, CC BY-SA 3.0
Photo: Perryjp, CC BY-SA 3.0
02 / 03
137 mph. Downslope wind
The gust the NCAR Mesa Lab in Boulder recorded on January 17, 1982. Winter winds off the Front Range work caps loose, lift flashing and drive snow into open seams.
Source: NCAR / NOAA records
Photo: Zach Dischner, CC BY 2.0
Photo: Zach Dischner, CC BY 2.0
03 / 03
½ inch. Wildfire season
The largest opening the building code allows in a spark arrestor screen. An intact cap screen keeps embers inside the flue, away from dry grass and roofs.
Source: IRC R1003.9.2
Photo: Zach Dischner, CC BY 2.0
Photo: Zach Dischner, CC BY 2.0
Chimneys, up close.
Photos from our Google Business Profile.
Tags with an arrow jump to that part in the chimney walkthrough.
Cap, in the chimney walkthrough Cap, in the chimney walkthrough 
Chase top 
Chase top Crown, in the chimney walkthrough 
Crown, in the chimney walkthrough 
Flue, in the chimney walkthrough Flue, in the chimney walkthrough 
Flue, in the chimney walkthrough 
Brick Smoke chamber, in the chimney walkthrough Firebox, in the chimney walkthrough
Boulder, from North Boulder to Table Mesa.
Boulder is the service area on our Google Business Profile: the city itself, from past the old brick of , and to , and next door.
Just outside the line? Call (983) 223-5376 and ask.
City of BoulderGunbarrelContours every 200 ft
Terrain: AWS Terrain Tiles. Boundaries: US Census Bureau TIGERweb. Place names: OpenStreetMap contributors.
- North Boulder
- Gunbarrel
- Newlands
- Mapleton Hill
- Whittier
- Goss Grove
- University Hill
- Chautauqua
- Martin Acres
- Table Mesa
- South Boulder
- Frasier Meadows
Photo: joiseyshowaa, CC BY-SA 2.0
Questions Boulder homeowners ask.
Straight answers, with the source when there is one.
How often should a chimney be swept?
The National Fire Protection Association recommends an inspection once a year. Sweeping depends on how much you burn: the Chimney Safety Institute of America rule of thumb is to sweep at 1/8 inch of buildup, sooner if the deposit looks glazed or shiny.
Source: NFPA 211, CSIA
Do I need an inspection when I buy or sell a house?
NFPA 211, the standard for chimneys and fireplaces, calls for a Level 2 inspection when a property is sold or transferred. It goes further than a yearly look, including a camera run of the flue.
Source: NFPA 211
Why does my fireplace smell, especially in summer?
Creosote in the flue gives off a smoky smell when the air is warm and humid, and a draft down the chimney carries it into the room. A sweep removes the source; a damper that seals and a cap help keep it outside.
Source: CSIA consumer guidance
What is a chimney crown, and why do they crack?
The crown is the concrete slab on top of the chimney that sheds water. Boulder winters freeze and thaw it over and over, and water inside a hairline crack expands about 9% as it freezes, so a small crack grows a little every cold night.
Source: Physics of ice
Is a chimney cap really necessary?
A cap keeps out rain, snow, birds and squirrels, and its screen works as a spark arrestor. The International Residential Code (R1003.9.2) sets the screen openings between 3/8 and 1/2 inch: small enough to stop embers, large enough not to clog.
Source: IRC R1003.9.2
Which areas do you serve?
Boulder, the service area on our Google Business Profile: the city from North Boulder down to Table Mesa, and Gunbarrel next door. Just outside those lines? Call (983) 223-5376 and ask.
How do I book?
Call (983) 223-5376 from 7 AM to 9 PM, every day, or send a request with the form on this page at any time. We will call you back to confirm a time.
Book a visit.
Tell us what you need and we will call you back to confirm a time.
- 1You book By phone or online.
- 2We call back To confirm a time.
- 3We inspect Cap to firebox, first.
- 4You decide What gets done, and when.
Online
24 hours a day, with this form
Photo: Chautauqua park with flatirons, Laurascudder (assumed author), CC BY-SA 3.0
Smoke smell, a cracked crown, or just the first fire of the year?
Office 7 AM to 9 PM, every day. Book online any hour.Office open now, until Office opens at . Book online now.
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