Our Non-Destructive Chimney Diagnostic Tools
Tools most homeowners have never seen on a chimney inspection. Professional instruments that measure what a visual inspection cannot, without cutting into your walls, ceilings, or chimney.
Why We Use These Tools
A typical chimney inspection relies on a camera and a careful look. That shows what a flue looks like, but many of the problems that matter most are hidden: heat reaching wood framing behind a wall, water soaking into the attic around the chimney, a liner that leaks or has thinned from corrosion.
Our diagnostic instruments measure those things directly. Most homeowners have never seen these tools on a chimney inspection, so this page explains what each one does and what it means for your home. Every hearth inspection is based on St. Louis City & County and St. Charles City & County currently adopted municipal code.
Non-Destructive Testing
Every tool on this page is non-destructive. We read through surfaces instead of opening them:
- No cutting into walls or ceilings to look for heat or water damage
- No removing the liner or connector to check its condition
- No fire needed to see where heat travels, since a controlled heat load does the job
- Less walking on your roof when the drone can capture the photos
When a problem is found, you get the readings, thermal images, and photos that show where it is, so any repair can be targeted to the right spot. If walls or a chase ever need to be opened to confirm a finding, we explain why and get your approval first.
What You Get
- Numbers, not just opinions: temperatures, moisture readings, clearances, draft, leakage, and metal thickness
- Pictures you can understand: thermal images and photos of the problem areas
- A written report you can keep for your records, your insurance, or a future home sale
The Instruments
Wöhler VIS 350 Inspection Camera
What it does: A video camera on a flexible rod that travels the full length of your flue and records video and still images.
Why it matters to you: You see the inside of your own chimney, including cracks, gaps, and creosote, with the depth of each finding marked.
Used in: Every inspection
FLIR E5-XT Thermal Imager
What it does: A thermal camera that shows surface temperatures as a color image, from -4°F to 752°F.
Why it matters to you: Heat moving into framing, drywall, or the attic shows up as a bright spot on the image, often before there is any visible sign of a problem.
Used in: Hearth Diagnostic Plus, Heat Load & Thermography Analysis, claim reports
Steinel HL 2020 E Heat Gun
What it does: A professional heat gun placed in the firebox and pointed up toward the damper to warm the system with a controlled heat load.
Why it matters to you: Warming the fireplace lets the thermal camera show where heat travels when the fireplace is in use, without needing a fire. This analysis documents heat-transfer paths under a controlled heat load. It does not reproduce the full operating temperatures of a fire.
Used in: Hearth Diagnostic Plus, Heat Load & Thermography Analysis
Tramex MEX5 Moisture Meter
What it does: A moisture meter that reads moisture in wood framing and drywall through the surface, with comparison readings on masonry and room humidity.
Why it matters to you: Finds hidden water coming in around the chimney before it turns into rot, mold, or stained ceilings, without cutting into the wall.
Used in: Hearth Diagnostic Plus, Moisture Mapping, claim reports
Bosch BLAZE Indoor Laser
What it does: A laser measure for precise interior distances.
Why it matters to you: Checks the clearance between your fireplace and nearby wood, trim, and mantels against code, with exact numbers in your report.
Used in: Hearth Diagnostic Plus
Bosch BLAZE Outdoor Laser
What it does: A laser measure with a camera viewfinder for use outdoors in daylight.
Why it matters to you: Measures chimney height and roof clearance from the ground or roof, so we can confirm the chimney is tall enough to draft properly and meet code.
Used in: Level 2, Hearth Diagnostic Plus
Wöhler DM 602 Digital Manometer
What it does: A digital gauge that measures draft and pressure inside the flue.
Why it matters to you: Shows whether smoke and exhaust are moving up and out the way they should, which helps explain smoky rooms, odors, and backdrafting.
Used in: Hearth Diagnostic Plus, gas appliance service
Wöhler DP 600 Leakage Tester
What it does: Seals the flue, holds a set test pressure, and measures the airflow needed to keep that pressure.
Why it matters to you: Gives a measured answer to how much your flue leaks, which helps you decide whether relining is needed before you spend money on it.
Used in: Flue Integrity Test, Flue Leakage Test, claim reports
Elcometer PTG8 Ultrasonic Thickness Gauge
What it does: Uses sound waves to measure the wall thickness of stainless liners, connectors, and other metal parts from one side.
Why it matters to you: Shows how much metal is left in a liner or connector, so corrosion or heat damage is measured instead of guessed, without removing the part.
Used in: Flue Integrity Test, claim reports
DJI Mini 3 Pro Drone
What it does: A small camera drone flown by a technician who holds an FAA Part 107 Remote Pilot Certificate.
Why it matters to you: Close-up photos of your crown, cap, flashing, and masonry when the roof is too steep or unsafe to walk, with less foot traffic on your shingles.
Used in: Level 2, Hearth Diagnostic Plus, claim reports
Where These Tools Are Used
All of these instruments are part of Hearth Diagnostic Plus ($529) and the Flue Integrity Test ($849). During a standard service, a technician may recommend a single add-on, such as Moisture Mapping ($129), Heat Load & Thermography Analysis ($149), or a Flue Leakage Test ($295), but only when they see a specific condition, and only with your approval. See pricing for every service.
Instrument readings document conditions at the time of testing. They support our findings but do not guarantee future performance.
Trained on Code, Not Just Equipment
Our CSIA-certified technicians train on NFPA 211, the International Residential Code, and the codes adopted by St. Louis City & County and St. Charles City & County. Each instrument has a written field procedure, so every test is set up, run, and documented the same way.
Frequently Asked Questions
No. Every tool we use is non-destructive. The instruments read through surfaces, so there is no cutting into walls, ceilings, or the chimney to run the tests.
Usually not. Our $299 Routine Chimney Sweep & Core Inspection includes an internal camera scan. A technician may recommend an add-on only if they see a specific condition, and we get your approval first.
No. A professional heat gun in the firebox applies a controlled heat load while the thermal camera documents where heat travels. When an appliance can be safely fired, its own heat may be used instead. The test does not reproduce the full operating temperatures of a fire.
The Flue Integrity Test ($849) includes everything in Hearth Diagnostic Plus plus a flue leakage test and liner thickness readings.
Yes. Our drone is flown only by a technician with an FAA Part 107 Remote Pilot Certificate.
Schedule a Diagnostic Inspection
Book online anytime, or call 636-946-1622 Monday through Friday 8 AM to 4 PM and Saturday 9 AM to 1 PM.