Curved brick chimney (C) Daniel FriedmanChimney Defects List & Home Inspection Education

  • DEFECTS LIST - CHIMNEYS - CONTENTS: List of chimney defects and home inspection points. Lists of important chimney, flue & venting defects for residential buildings. What does a home inspector need to know about chimney inspection & hazards? Home inspection training and education curriculum recommendations
  • POST a QUESTION or READ FAQs about home & building inspection courses, standards, & defect checklists for chimney, flue & vent inspections

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This article lists significant chimney defects, definitions, and home inspection education topics.

This article series, beginning at BUILDING DEFECTS LISTS, provides lists of common building defects and basic defect knowledge that also outline recommended curriculum content for home inspector education. The building defects and inspection points listed in these articles also guide homeowners and home buyers to building areas that merit careful attention and often point areas of safety concern or important maintenance and repair tasks.

Shown at page top: a curved brick chimney, most likely due to sulphation. The flue in a curved masonry chimney may be damaged and thus the chimney would be unsafe, risking fire or even fatal flue gas hazards.

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Home Inspection Education Curriculum - Chimneys

4.4   Chimneys: inspection recommendations & list of typical defects

4.4.1 Knowledge Base for Inspecting Chimneys & Flues

1.    Describe the function of chimneys and vents.

2.    Describe metal and masonry chimneys including the materials and components such as footing and foundation, vent connector, chimney walls, flue liner, cap or crown.

3.    Describe the features of  adequate installation and repair techniques for chimneys and vents.

4.    Define the following terms with respect to chimneys and vents: chimney, flue, vent, vent connector (exhaust flue, vent pipe, stack pipe, flue pipe, chimney connector, breaching)JDG, creosote, draft, lateral support, bracing, fire stopping, clay tile, chimney offset, combustible clearance, cap (crown), cement wash, corbeling, spalling, efflorescence, minimum height above roof, ashpit, ash dump, ashpit clean out door, raincap, spark arester, shared flues, type B vents, type L vents, class A chimneys, super chimney(metal).

5.    Identify the codes or standards which apply to masonry and metal chimneys in your area.

4.4.2 Inspection Skills for Chimneys & Flues & Vents

1.    Describe the inspection procedure for masonry and metal chimneys above.

2.    Identify the common defects listed on the next page.

3.    Describe the implication of each defect.

4.    Identify safety issues for the inspector and the occupant of the home(chimney fire, fall hazard, chimney collapse, combustion products poisoning occupant, fire).

4.    Communicate findings to client verbally and in writing, recommending corrective action where needed.



• Adjacent chimneys with staggered, height

• Cap missing, obstructed or wrong type

• Chimney walls rusting or pitting

• Chimney not well supported

• Creosote build-up

• Excessive offset from vertical

• Inadequate combustible clearances     

• Inadequate fire stopping

• Inadequate total chimney height

• Inadequate chimney height above roof

• Not continuous through roof

• Not labeled for application

• Sections not well secured

• Too many appliances on one flue

MASONRY CHIMNEY Defects                

• Abandoned openings for flue connections

• Ash pit door too close to combustibles,

Chimney cap or top seal or crown loose or missing       

• Cap missing or cracked  

• Chimney extender rusted or stuck       

• Chimney too short above roof                 

• Cracking                               

• Creosote build-up                            

• Draft inducer fan inoperative                

• Efflorescence                          

• Excessive offset from vertical (30%)         

• Fire stopping missing or incomplete          

• Flue or vent connector obstructed      

• Improper slope on cap                  

• Inadequate combustible clearance       

• Loose, missing or deteriorated mortar

• Loose, missing or deteriorated masonry

• No capillary break on cap

• No chimney liner

• No drip edge on cap

• Pulling away from house

• Settling or leaning

• Spalling

• Too many appliances on one flue

• Total chimney height too short

• Vent connectors extending into chimney

• Vent connectors loose at chimney      

Some Important Chimney Articles


Also see HOME & BUILDING INSPECTORS & INSPECTION METHODS. Use the Search Box at the top or bottom of these pages to find in-depth information about building, energy savings, and indoor environment inspection, diagnosis and repair at this website. Watch out: these inspection lists do not list all possible defects for the systems discussed, and not all home or building inspectors will examine all of the items listed here. CONTACT us to suggest corrections or additions to articles at this website.

These curriculae and building defect lists are based on smilar curriculum documents first prepared by Joe Scaduto, an ASHI member who prepared course material for Northeastern University's Building Inspection Certificate program in 1988, subsequently by DF, InspectApedia's editor, for New York University ca 1988 and later, with others, recommended to ASHI, the American Society of Home Inspectors. ASHI did not adopt this material though currently that association as well as others offer extensive HOME INSPECTOR EDUCATION material.

The curriculum and lists of defects are informed by additional analysis of the process of home inspection that was developed beginning Calgary, AB for Canadian and U.S. home inspector education and certification examinations in 1997. Other early contributors to home inspection education in the U.S. and Canada include Dr. Jess Aronstein, Alan Carson, Mike Casey, Mark Cramer, John Cox, Dwight Barnett, Douglas Hansen, Rick Heyl, Larry Hoytt, Bill Merrill, Kevin O'Malley, Dennis Robitalille, Keith Peddie, Pat Porzio, Roger Robinson.


Continue reading at CHIMNEY INSPECTION DIAGNOSIS REPAIR - home, for our complete list of articles on this topic, or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.



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