A chimney is a system — not just a decorative feature above your roofline. It vents combustion gases from fireplaces, wood stoves, furnaces, and water heaters, and it does this safely only when it’s in good structural condition, properly lined, and free of blockages and creosote buildup. When it isn’t, the consequences range from carbon monoxide entering the living space to chimney fires that can spread to the structure of the home.

Yet chimney maintenance is one of the most neglected areas of home care — and one of the most aggressively marketed by unqualified operators. A door-to-door “chimney inspector” who tells you your chimney needs $3,000 in repairs after a five-minute visit, without a proper camera inspection or documented findings, is running a well-documented fraud pattern.

The questions in this guide apply whether you’re hiring for annual chimney sweeping, a camera inspection, relining, tuckpointing, crown repair, damper replacement, gas fireplace service, or a full chimney rebuild.

“The chimney is the one system in the home that connects a combustion source directly to the living space and the structure. When it works correctly, it’s invisible and you never think about it. When it doesn’t, the consequences can be catastrophic. The inspection — a real inspection with a camera into the flue — is the foundation of everything. Any chimney company that tells you what’s wrong without running a camera is guessing. And guessing in a chimney is dangerous.”

— Bridget Oyelaran, WETT-certified chimney inspector and fireplace technician with 16 years of experience in residential chimney inspection, cleaning, and repair in the local area

Before You Call Anyone

a living room filled with furniture and a fire place

How old is your chimney, and when was it last inspected?

Most chimney systems should be inspected annually — not necessarily cleaned annually (that depends on use), but inspected. If your chimney hasn’t been inspected in the last few years, start there.

Common age-related issues by era:
– Pre-1960 homes: Many older chimneys have no liner, or an original clay tile liner that may be cracked or deteriorating
– 1960s–1980s homes: Many gas appliances were converted from oil during this period, often without relining the chimney for the lower flue temperatures gas appliances produce (a cause of moisture problems and liner deterioration)
– All ages: Masonry deteriorates with freeze-thaw cycling, and mortar joints erode over time

What are you actually using the chimney for?

Different appliances have different chimney requirements:

Wood fireplace or wood stove: Highest temperature, highest creosote risk. Requires a properly sized liner rated for solid fuel.

Gas fireplace or gas furnace: Lower temperatures than wood, but still produces corrosive combustion products. Requires a liner appropriate for the appliance’s BTU output and flue gas temperature.

Oil furnace: High efficiency modern oil furnaces produce cooler flue gases that can cause condensation in an oversized or older liner. May require relining when upgrading.

Decorative (not burning) fireplace: Still requires inspection for structural integrity and to ensure no animal intrusion.

Questions to Ask Before Hiring

low angle photo of house

Are you WETT-certified?

WETT (Wood Energy Technology Transfer) certification is the primary professional credential for chimney and wood energy system inspectors and technicians. WETT-certified professionals have completed training and examination in chimney inspection, wood burning systems, and related codes.

Ask specifically: do you hold current WETT certification? For installation or inspections related to wood-burning appliances and insurance purposes, WETT certification is often required.

What a good answer looks like: Current WETT certification with a certification number that can be verified at wettinc.Ca.

Are you a licensed business with insurance and workers’ compensation coverage?

Chimney work often involves roof access and elevated work. Liability insurance is essential. Workers’ compensation coverage covers workers if injured.

Ask for a certificate of insurance and workers’ compensation coverage Clearance Certificate.

What inspection method do you use?

There are three levels of chimney inspection, as defined by the National Fire Protection Association (NFPA 211) and referenced by Canadian standards:

Level 1: Visual inspection of accessible portions of the chimney exterior and interior (what can be seen from the firebox and from the top). No tools required. Appropriate only for chimneys in use without changes to appliance or venting system. Not adequate for assessing liner condition.

Level 2: Includes all of Level 1, plus video camera inspection of the interior of the flue throughout its length. This is the minimum standard for any meaningful assessment of liner condition. Required when selling a home, when making any change to the appliance or venting system, and after any event that could have damaged the chimney (fire, earthquake, nearby lightning strike).

Level 3: Includes all of Level 2, plus removal of components (caps, liners, dampers) as needed to fully access and inspect the chimney. Required when significant damage is suspected.

Ask specifically: will you perform a camera (Level 2) inspection, and will I see the footage or a report from it?

What a good answer looks like: A Level 2 video inspection as standard for any new client or any chimney that hasn’t been recently inspected, with footage or a written report provided.

For more: Questions to Ask a Chimney Inspector About the Inspection Process

Questions About Common Repairs

For relining: what liner system are you recommending, and why?

If relining is recommended, ask specifically what liner material is being proposed:

Stainless steel flexible liner: The most common residential relining solution. Appropriate for wood-burning fireplaces, gas appliances, and oil furnaces, depending on the grade of steel and the liner rating. Ask what alloy the liner is (316L stainless is appropriate for most applications; 904L is required for oil appliances).

Cast-in-place liner: A poured concrete or castable refractory product that fills the existing flue, creating a seamless liner within the old chimney. Very durable, appropriate for masonry rehabilitation. More expensive.

Clay tile replacement: Replacing damaged clay tile sections. Appropriate for isolated damage in otherwise sound tile liners.

Ask why the recommended liner type is appropriate for your specific appliance and chimney dimensions.

For more: Questions to Ask a Chimney Contractor About Relining and Repairs

For masonry work: what is the scope and what materials are being used?

For tuckpointing (repointing deteriorated mortar joints), ask what mortar type is being used — a Type S or N mortar appropriate for chimney masonry, not standard construction mortar. Inappropriate mortar in a chimney can deteriorate rapidly in the heat and freeze-thaw cycling a chimney experiences.

For crown repair, ask whether the crown is being patched or replaced. A cracked chimney crown — the concrete cap at the top of the chimney that seals the masonry from rain — should be replaced when significantly cracked, not patched.

Questions About Gas Fireplace Service

Are you qualified to service gas fireplaces?

Gas fireplace service involves working on gas appliances and connections — which in many regions requires a gas technician licence (gas technician or G1 for more complex work). Ask whether the technician servicing your gas fireplace holds the appropriate gas technician licence.

What a good answer looks like: Confirmed gas technician or G1 licence for gas fireplace service and repair work.

For more: Questions to Ask About Gas Fireplace Service and Repair

Red Flags to Watch For

Telling you what’s wrong without a camera inspection. Any company that diagnoses significant chimney problems — liner deterioration, major structural damage — without running a camera into the flue is guessing. Structural and liner conditions cannot be assessed by looking from the top or from the firebox. A camera inspection is the only reliable diagnostic tool.

Door-to-door inspection offers. Unsolicited door-to-door chimney inspection offers — particularly those that arrive shortly after a neighbor’s chimney fire or after a news story about chimney safety — are a well-documented fraud pattern. Legitimate chimney companies don’t cold-canvas for clients this way.

A very low “inspection” fee followed by expensive repair recommendations. Some operators charge $50–$100 for an “inspection” and then show you alarming (and often fabricated) footage of a chimney in poor condition to justify several thousand dollars in repairs. Get a second opinion from a WETT-certified company before agreeing to any significant repair.

No written report from the inspection. A professional chimney inspection results in written documentation — what was inspected, what was found, what was recommended, and with what urgency. A verbal report with no documentation protects nobody and creates no accountability for the diagnosis.

Recommending a full reline for every chimney. Full chimney relining is a significant expense ($2,000–$6,000 or more). It’s appropriate when the liner is genuinely deteriorated. It is not appropriate for every chimney that’s over 20 years old. A company that recommends relining for every chimney it inspects is not doing honest assessments.

For a full guide: Red Flags When Hiring a Chimney or Fireplace Contractor

Before They Start: A Quick Checklist

  • WETT certification verified at wettinc.Ca
  • Business registration and insurance verified
  • Workers’ compensation coverage clearance verified
  • Camera (Level 2) inspection confirmed before any repair recommendations are accepted
  • Written inspection report requested
  • Specific repair scope agreed in writing before any work begins
  • Gas technician licence confirmed for any gas appliance work

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