How to Read a Chimney Inspection Report

Start with the level

Before reading a single finding, find where the report states the inspection level. Everything else in the document is bounded by it.

NFPA 211 defines three, and they differ in how much of the system was actually accessible to the inspector.

Level I is the routine annual inspection, appropriate when the appliance and fuel are unchanged and nothing unusual has happened. It covers readily accessible portions of the chimney exterior and interior, and accessible portions of the appliance connection. The inspector verifies the structure is sound, the flue is free of obstruction and combustible deposits, and the basic installation is intact.

Level II is required on specific triggers: sale or transfer of the property, a change of appliance or fuel type, or after an operating malfunction or an external event that could have damaged the chimney — a chimney fire, a seismic event, or severe weather. It includes everything in Level I plus accessible attics, crawl spaces, and basements, and — the part that matters most — video scanning of the internal flue surfaces. Our comparison of Level I vs Level II inspections goes into the triggers in more detail.

Level III involves removing or opening concealed components — masonry, panels, or parts of the structure — and is reserved for cases where a serious hazard is suspected and cannot be evaluated any other way. It is not a routine service.

The practical consequence: a clean Level I report is a real statement, but it is a statement about what was readily accessible. It does not carry the same weight as a clean Level II with camera footage of the full flue. If you are buying a house, that distinction matters a great deal — see chimney inspection before buying a home in Illinois.

The components, and what a finding on each means

A well-structured report walks the system in order. Here is what each part is for, so a finding against it means something to you.

Flue and liner. The sealed path carrying combustion products out. Findings here are the most consequential on the whole report, because the liner is what separates hot gas from your house. Cracks, gaps, displacement, or missing sections are serious. Deposit buildup is graded by stage, and the later glazed stages do not brush out — chimney creosote stages covers the progression.

Smoke chamber. The transition between firebox and flue. It should be smooth and parged; rough or corbelled surfaces disturb the gas flow and give deposits somewhere to collect. See smoke chamber parging explained.

Damper. Should open fully, close fully, and seal. A damper that will not close wastes conditioned air year-round; one that will not open fully is a draft and safety problem. Chimney damper repair covers the failure modes.

Firebox. The combustion chamber itself. Cracked refractory panels or deteriorated mortar joints between firebrick are the usual findings — fireplace firebox repair.

Crown. The sloped masonry cap at the top that sheds water away from the structure. Cracks route water directly into the chimney. Cracked chimney crown.

Cap. Keeps rain, snow, and animals out of the flue and typically carries a spark arrestor. Frequently missing or corroded on older stacks. Chase cover vs chimney cap distinguishes the two components, which are often confused.

Flashing. The waterproof detail at the roof junction. The most common leak path on the entire assembly, and the damage usually shows up as an interior ceiling stain long before anyone inspects the chimney. Chimney flashing leak.

Exterior masonry. Mortar joints, brick faces, and overall plumb. Findings here range from cosmetic to structural, and the distinction is whether the brick faces themselves are still sound. Chimney tuckpointing and spalling chimney brick cover the two ends of that range.

Terminology worth knowing

A few terms recur and are worth having straight.

Spalling — brick faces flaking or breaking away, usually because water entered the brick and froze. Distinct from mortar erosion, and more serious, because it means the brick unit itself is failing rather than the joint between units.

Efflorescence — white crystalline deposit on the masonry surface, left when water moves through the material and evaporates. A moisture indicator rather than a defect on its own. Chimney efflorescence.

Repointing / tuckpointing — removing deteriorated mortar to a specified depth and replacing it. The mortar has to be matched to the existing masonry; a mix harder than the surrounding brick transfers stress into the brick faces and causes damage over subsequent years. ASTM C270 is the specification that governs the match, which is why you will see it cited on scopes.

Parging — a smooth mortar coating applied to a surface, most often the smoke chamber.

Corbelling — stepped masonry courses that project outward. Normal construction in many chimneys; noted because rough corbelled surfaces inside a smoke chamber affect flow.

Draft — the pressure difference that moves combustion gases up and out. Poor draft has many possible causes, several of them unrelated to the chimney itself. Chimney draft problems.

Questions worth asking

Once you have read the report, a short list of questions usually resolves whatever is left ambiguous.

Which level was performed, and was any part of the system inaccessible? If something could not be examined, the report should say so, and you should know what was left out.

Can I see images of each defect? For anything driving a repair recommendation, ask. This is the single most useful request you can make.

Can I use the appliance right now? This should have an unambiguous yes or no. If the answer is qualified, ask what the qualification is.

Which findings are urgent, which are seasonal, and which are monitoring items? A good report already separates these. If yours does not, ask for the sorting — we cover the three tiers in what happens when your chimney fails inspection.

What mortar specification will be used? For any repointing scope, the answer should reference matching the existing masonry rather than a generic modern mix.

You can verify licensing independently through the IDFPR licence lookup.

Keep the reports

A single inspection report is a snapshot. A run of them is a trend line, and the trend is what actually tells you whether something is deteriorating or holding steady.

A hairline crown crack noted three years running and unchanged is a different situation from one that has visibly opened since last autumn. Photographs make that comparison possible; text alone rarely does. Keeping the file also matters at sale, when a documented maintenance history is straightforwardly useful — see chimney inspection before selling your home.

The decision

Read the level first, then the components, then ask the five questions. If the report leaves you unable to say whether you can light a fire this weekend, it has not done its job, and the person who wrote it should be willing to clarify.

If you have not had an inspection this year, the annual standard applies regardless of how much you burned last season — a chimney that sat unused still weathered a Chicagoland winter.

Delta - Chimney Repair and Services performs NFPA 211 inspections across the North Shore and northwest suburbs and has dispatched from our Park Ridge office since 1987. If you have a report from another company and want the findings explained in plain terms, that is a reasonable thing to ask for.

Check which level was performed before you decide what "no defects noted" is telling you.