MINNEAPOLIS · TIER 3 CHIMNEY INSPECTION

Chimney Inspection — Tier 3 in Minneapolis

Concealed chimney areas opened, investigated, and restored to scope.
Every Tier 3 starts with a written scope authorization — you know what opens before we touch anything.
THE NFPA 211 LADDER

What Makes a Tier 3 Inspection Different from Every Other Type

A Tier 3 — NFPA 211 Level 3 — requires removing building components to reach areas a camera cannot.
LEVEL 1

Visual

Accessible surfaces examined by eye — no tools, cameras, or removal.

LEVEL 2

Adds a Camera

A camera scan down the flue assesses the liner and accessible interior — still no demolition.

LEVEL 3

Opens the Structure

Building components are removed to reach concealed zones a camera cannot access.

Concealed chimney areas are the structural spaces hidden inside the system — wall cavities behind the firebox, attic chase interiors, and spaces beneath the hearth slab. They can’t be seen, probed, or filmed until something surrounding them is removed. This is the investigation of last resort: when visible surfaces and camera footage leave a critical question unanswered, a Tier 3 is the only way to answer it.
Level 3
NFPA 211 Investigation
Signed Scope
Before Anything Opens
Documented
Every Concealed Zone
Restored
To a Finished State
WHAT TRIGGERS A TIER 3

Post-Winter Minneapolis Conditions That Trigger a Tier 3 Assessment

Two situations reliably trigger a Tier 3: chimney-fire aftermath and a Level 2 finding a camera couldn’t reach.
Chimney-fire aftermath doesn’t announce itself on the exterior — the chimney can look completely intact the morning after. But even a brief fire generates enough heat to crack liner sections, breach mortar joints, and stress adjacent framing, all in areas hidden behind the liner or within the wall cavity. The extent of that damage can’t be confirmed from any accessible surface.
Minneapolis winters compound it. Older homes here — craftsman bungalows, foursquares, Tudor revivals — were built with masonry walls, attic chases, and basement footings that create multiple concealed zones around the chimney, and a severe cold season pressures all of them at once.
Carbon-monoxide pathways are the third trigger. A CO pathway is a breach — cracked liner, open joint, or failed fire stop — that routes combustion gases into living spaces instead of up the flue. A fire stop is the horizontal barrier inside the chimney structure that blocks flame and gases from traveling vertically through wall cavities during a fire; when one fails, it fails invisibly. When unexplained CO readings can’t be traced to accessible surfaces, the source is likely concealed.
Chimney-fire aftermathUnreachable Level 2 findingCarbon-monoxide pathway
WHEN THE STRUCTURE IS OPENED

What ChimTech Looks for When the Structure Has to Be Opened

Every observation is documented — with location, component, and structural implication — before any restoration.
Portrait of Brian Levi, founder of ChimTech
Brian Levi
Founder, ChimTech
The investigation doesn’t start with a hammer. It starts with the Level 2 report — or the post-event account from the homeowner — and works backward to identify which concealed zones are most likely to hold the damage in question. Then the scope is set.

Wall Cavity Behind the Firebox

Cracked masonry, displaced liner sections, and breached mortar joints that let combustion gases migrate laterally — only visible once the surrounding structure is removed.

Attic Chase Interior

Where the chimney runs through a finished attic floor: displaced fire stops, fire-compromised framing, and liner offsets that created gaps between tile segments.

Beneath the Hearth Slab

The chimney footing and structural continuity of the base — where, on a multi-flue masonry base, a footing failure affects the entire stack.

NOTHING OPENS WITHOUT A SIGNATURE

Scope Authorization Before Any Deconstruction Begins — Always

ChimTech does not open a wall, remove a component, or break a joint without a signed scope authorization in hand.

What Opens?

Every area to be opened is named in the authorization document before the crew touches anything.

Why Does It Need To Open?

Each opening is tied to the specific concealed zone most likely to hold the damage in question.

What Gets Put Back?

Restoration for each zone is defined up front — wallboard replaced, masonry repointed, finished state restored.

Scope authorization converts a potentially complex process into a defined, predictable project. Authorizing a Tier 3 isn’t handing a crew unlimited access — it’s approving a specific, documented scope, and ChimTech does not deviate from it without a conversation first. That matters in Minneapolis, where a Tier 3 is often triggered by an insurance event — a chimney-fire claim, a CO incident, a pre-sale finding — and the authorization document is the record that ties the investigation to the concern that prompted it.
THE DOCUMENTED SEQUENCE

How ChimTech Plans and Documents a Tier 3 Investigation

A documented sequence — assessment, authorization, access, findings, restoration — in that exact order.
BEFORE THE INVESTIGATION

Review of all prior inspection findings and event documentation.

On-site pre-investigation assessment to identify target zones.

Written scope authorization prepared and reviewed with the homeowner.

Restoration path confirmed for each area to be opened.

DURING THE INVESTIGATION

Targeted removal of building components per the authorized scope.

Real-time documentation of each concealed zone as access is gained.

Photographs and written notes at every finding location.

No additional areas opened without homeowner notification and approval.

AFTER THE INVESTIGATION

Complete written findings report naming each observed condition by location.

Clear statement of which conditions require repair and which are within tolerance.

Restoration of opened areas to a defined finished state.

Homeowner receives a copy of the full investigation record.

AUTHORIZATION TO RESTORATION

From Authorization to Restoration — the Full Tier 3 Sequence

Three defined phases: diagnostics, implementation, and post-investigation closure.
01

Diagnostics

Begins before any deconstruction. ChimTech reviews the triggering event — chimney-fire documentation, a prior inspection report, or an account of unexplained CO readings — and a pre-investigation site visit identifies the target zones and produces the scope authorization. The phase ends when you sign the scope and the crew has a clear written mandate.

02

Implementation

The physical investigation. Components are removed in the sequence the scope specifies; each concealed zone is accessed, examined, and documented. When a finding warrants expanding to an adjacent area, that conversation happens before the scope expands. Pre-1940 Minneapolis homes often have irregular flue geometry and multi-layer walls requiring careful, methodical disassembly — nothing is removed that doesn't need to be.

03

Post-Investigation Closure

Once all target zones are assessed, opened areas are restored — wallboard replaced, masonry repointed where disturbed, structure returned to a finished state. The written findings report is delivered, and the scope authorization, findings record, and restoration notes are provided as a single project file.

WHERE WE INVESTIGATE

Tier 3 Investigation Coverage Across Minneapolis Properties

Tier 3 investigations are scheduled at properties within Minneapolis city limits — one crew, every phase.
Tier 3 scopes require continuity across the full project. The technician who reviews the Level 2 report and prepares the scope authorization is the same technician who opens the structure and delivers the findings — continuity that isn’t possible with a subcontracted or regionally dispatched crew.
The older residential stock in neighborhoods like Longfellow and Northeast — foursquares and craftsman bungalows with multi-zone chimney structures — represents the most frequent Tier 3 scenarios we handle. These homes were built with wall assemblies and attic configurations that create exactly the concealed zones a Tier 3 is designed to access. Homes in the 55406, 55407, 55412, and 55418 zip codes are within the standard service area.
South MinneapolisNortheastLongfellowNokomisLinden HillsKenwoodUptownNorth Minneapolis
Uncertain whether your address falls within scheduling range? Call (763) 402-9301 to confirm.

Authorize a Tier 3 Investigation with Full Scope Clarity

A Tier 3 is a significant step, and ChimTech walks you through the full scope before anything is authorized. Tell us what triggered the concern — a chimney fire, an unexplained CO reading, or a prior finding the camera couldn’t fully document. We’ll assess whether a Tier 3 is warranted, prepare the authorization, and review it with you before any work begins. Prefer email? Reach us at office@chimtech.org.
FAQ

Tier 3 Inspection Questions from Minneapolis Homeowners

A Tier 3 is triggered when a Level 2 camera inspection identifies damage in a concealed zone that can’t be examined without removing building components, or after a chimney fire where interior structural damage must be confirmed. Unexplained carbon-monoxide readings that can’t be traced to accessible surfaces are a third common trigger.

Depending on where the suspected damage is, ChimTech may need to remove wallboard behind or beside the firebox, open an attic chase section, or access the area beneath the hearth slab. The scope authorization document specifies exactly which components will be opened before any work begins.

Yes. Restoration is a defined part of every Tier 3 scope. Wallboard is replaced, masonry is repointed where disturbed, and each opened area is returned to a finished state. The restoration path for each zone is confirmed in the scope authorization before the investigation begins.

A Tier 2 uses a camera inside the flue to assess the liner and accessible interior without removing any building components. A Tier 3 goes further: physical removal of structure is required to reach concealed zones the camera can’t access. Tier 3 is reserved for situations where Tier 2 findings or a specific event make non-destructive methods insufficient.

Yes. ChimTech provides a complete written findings report identifying each observed condition by location, along with the signed scope authorization and restoration notes. This project file is structured to support insurance claims related to chimney-fire events or CO incidents.

Timeline varies with the number of zones investigated and the construction of the home. Homes built before 1940 often have multi-layer wall assemblies that require more careful disassembly. ChimTech confirms the estimated duration during the pre-investigation site visit, before the scope authorization is signed.