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CHIMNEY INSPECTION DIAGNOSIS REPAIR
ABANDONED CHIMNEYS, Indoors
ABANDONED CHIMNEYS, Outdoors
ANGLED CHIMNEY FLUES
ARCHITECTURE & BUILDING COMPONENT ID
Attic Chimney Inspection
BACKDRAFTING HEATING EQUIPMENT
Blocked Chimney Flues
BRACKET CHIMNEY Collapse & Fire Risks
B-Vent Clearances Table
CARBON MONOXIDE - CO
CHIMNEY CAP & CROWN
CHIMNEY CHASE Construction & Defects
CHIMNEY CLEANING PROCEDURES
Chimney Cleaning Fraud Warning
CHIMNEY CLEANOUT DOORS
Chimney Components Definitions
CHIMNEY CRACK DIAGNOSIS
CHIMNEY FLASHING Mistakes & Leaks
CHIMNEY HEIGHT & CLEARANCE CODE
CHIMNEY HEIGHT EXTENSIONS
CHIMNEY INSPECTION CHECKLIST
Most Frequent Chimney Defects
Chimney Inspection Checklist - Outdoors
Chimney Inspection Checklist - Indoors
Responsibility of an ASHI Home Inspectors
CHIMNEY INSPECTION, FLUE
CHIMNEY INSPECTION CAMERA
CHIMNEY INSPECTION, INDOORS
CHIMNEY INSPECTION, from GROUND
CHIMEY INSPECTION, ROOFTOP
CHIMNEY LEANING, SEPARATION
CHIMNEY REPAIR FRAUD WARNING
CHIMNEY REPAIR METHODS
CHIMNEY SAFETY - CPSC Alert
CHIMNEY SHOULDER LEAKS
CHIMNEY SHROUD, Decorative
CHIMNEY STAINS & LEAKS
CHIMNEY TYPES & MATERIALS
COMBUSTION AIR DEFECTS
COMBUSTION AIR for TIGHT buildings
COMBUSTION GASES & PARTICLE HAZARDS
COMBUSTION PRODUCTS & IAQ
COMPLETE COMBUSTION, Stoichiometric
CREOSOTE FIRE HAZARDS
Curved Brick Chimneys - Sulphation
Dead End Chimney Flue Hazards
DIRECT VENTS / SIDE WALL VENTS
DRAFT HOODS - gas fired
DRAFT MEASUREMENT, CHIMNEYS & FLUES
DRAFT REGULATORS, DAMPERS, BOOSTERS
EFFLORESCENCE, Salts & White / Brown Deposits
EMERGENCY RESPONSE, IAQ, GAS, MOLD
FIRE CLEARANCES INDOORS
FIRE CLEARANCES for MASONRY CHIMNEYS
FIRE CLEARANCES, METAL CHIMNEYS
FIRE CLEARANCES, SINGLE-WALL METAL FLUES
FIRE CLEARANCE WOOD & COAL STOVE FLUES
FIREPLACES & HEARTHS
FIRE STOPPING in BUILDINGS
FLAME COLOR, BLUE vs YELLOW COMBUSTION
FLASHING, CHIMNEY Mistakes & Leaks
FLUE SIZE SPECIFICATIONS
Flue Separation Requirements
Flue Tile Damage in Chimneys
FLUE VENT CONNECTORS, HEATING EQUIPMENT
FUEL CHANGES for HEATING APPLIANCES
HEATING COST FUEL & BTU Cost Table
HEATING SYSTEM INSPECTION
HOME HEATING SAFETY
INDOOR AIR EMERGENCY RESPONSE
Lennox SAFETY WARNING
METAL CHIMNEYS & FLUES
NOISE / SOUND DIAGNOSIS & CURE
ODORS & SMELLS DIAGNOSIS & CURE
ODORS FROM HEATING SYSTEMS
OIL HEAT SAFETY INSPECTIONS
PLASTIC HEATER VENTS
ROOF STAINS from CHIMNEYS
SAFETY RECALLS CHIMNEYS VENTS HEATERS
SHARED CHIMNEY & FLUE HAZARDS
STAIN DIAGNOSIS on BUILDING EXTERIORS
STAINS on/near CHIMNEYS
Three-Sided Chimneys: Problems
TRANSITE PIPE CHIMNEYS & FLUES
UNLINED FLUE INSPECTIONS
WOOD, COAL STOVES & FIREPLACES
WOOD STOVE SAFETY
This article describes the discovery, inspection, and significance of abandoned chimneys in buildings. By "abandoned chimney" we do not mean simply a chimney that is not in use.
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Our photo (at page top) shows the abandoned chimney in the attic below the corrugated metal roof in the photo shown in our outdoor chimney inspection section.
[Click to enlarge any image]
Happily this chimney was not in use at the time of our inspection. Do you suppose someone might some day try to use this flue without checking it out first?
Carson Dunlop's sketch (left) demonstrates the need to repair the roof and add support where a through-roof chimney is removed above the roof line.
Abandoned chimneys may be discovered in an attic, basement, or even in the middle of a structure, and can be a big surprise. We often wonder what's holding up all this weight.
Someone may have eliminated a fireplace or an entire chimney on the lower floors, but neglected to remove the chimney from the attic out through the roof, perhaps because they didn't want to repair the ensuing hole in the roof left if the chimney were removed.
Point loads from unanticipated weight or even a sudden collapse can be a real hazard if chimney bricks suddenly come through an upper floor bedroom ceiling.
Our photo (above) shows an unsupported chimney in the top floor of a pre-1900 home. This chimney has it all (bad): the masonry chimney rests on floorboards between floor joists - it does not support its own weight. The chimney is cracked, damaged, and has evidence of a fire.
The hole in the floor at the base of the chimney was a passage for a woodstove flue vent connector (with no fire protection or clearance) that connected into the upper opening in the chimney.
Look for unsupported or inadequately supported masonry left in the building, sagging floors, or worse, on occasion you may find that the chimney was only "abandoned" above the roof, and that it continues to vent into the building attic. We found just that condition in a chimney trying to vent a gas fired furnace.
Our photo (above left) shows fiberglass stuffed into a round hole in a building surface. Regardless of whether you see this clue in a floor, ceiling, or wall, some investigation for the presence of a chimney behind the opening is an important safety check. Older homes were sometimes constructed with a single flue chimney that served appliances on multiple floors - an unsafe practice that is prohibited by modern building and fire codes.
[Click to enlarge any image]
Carson Dunlop's sketch (above right) shows a common "pie plate" cover over an un-used chimney opening. For safety the opening should be filled in with masonry. Be sure the repair leaves masonry flush with the chimney interior, not just the chimney's exterior side. Otherwise the repair may interfere with draft and it may make cleaning the flue difficult or impossible.
When an upstairs woodstove is removed the hole left in the chimney is best sealed with masonry material, not a metal cover plate, not insulation, not wood or drywall. Closing a chimney opening with those less durable materials leave a fire and flue gas leakage risk in the building.
Some of the hazards associated with incomplete removal of a masonry or even a metal chimney in a building include:
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Technical Reviewers & References
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