Abandoned chimney in attic (C) Daniel Friedman Inspection & Assessment of Abandoned Chimneys in buildings
     

  • ABANDONED CHIMNEYS - CONTENTS: Definition of abandoned chimney or flue - Where do we find abandoned chimneys in buildings? What are the risks associated with abandoned chimneys? List of Abandoned Chimney Hazards. Abandoned flue opening hazards & closure procedures.
  • POST a QUESTION or READ FAQs about abandoned chimney detection, inspection, hazards, removal or repair
  • REFERENCES

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

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.

Green links show where you are. © Copyright 2015 InspectApedia.com, All Rights Reserved.

Inspection & Assessment of Abandoned Chimneys in buildings

Abandoned chimney removal at roof (C) Carson Dunlop AssociatesA greater concern are chimneys that have been only partially removed, may not be adequately supported, and risk collapse, fire spread, heat loss, and other building concerns.

Our photo (at page top) shows the abandoned chimney in the attic below the corrugated metal roof in the photo shown in our separate
ABANDONED CHIMNEYS, OUTDOORS article.

[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.

Unsupported chimney (C) Daniel FriedmanSomeone 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.
There is also danger of chimney collapse, damaging the structure and injuring building occupants should masonry chimney parts fall through floors or ceilings below.

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.

At CHIMNEY CLEANOUT DOORS

and

at FLUE VENT CONNECTORS, HEATING EQUIPMENT we show a closeup of the lower cleanout opening - which was blocked by falling debris.

Fire & Gas Hazards of Abandoned Chimney Flue Openings

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.

Hole may mark abandoned chimney or flue (C) Daniel Friedman Abandoned chimney openings in bulidings (C) Carson Dunlop Associates

Our photo (above left) shows fiberglass stuffed into a round hole in a building surface. [Click to enlarge any image]

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.

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.

A List of Abandoned Chimney Hazards on buildings

Some of the hazards associated with incomplete removal of a masonry or even a metal chimney in a building include:

  • Fire spread in the building: an un-sound chimney may speed the spread of a building fire between floors
  • Air quality and air safety: an un-used chimney may increase the flow of toxic gases from a problem area upwards into other building rooms, such as a smoke, soot, or potentially fatal carbon monoxide generated by heating appliance that is malfunctioning in a lower building area. Drafts can also move moisture and toxic mold spores or allergens and other problematic particles in a building.
  • Bracket chimneys: old incomplete and possibly inadequately supported masonry chimneys in buildings -
    see BRACKET CHIMNEYS for details.
  • Structural collapse: an old chimney may collapse causing damage or even injury to people at lower floors in the building.
    See CHIMNEY COLLAPSE Risks, Repairs
 

 

Continue reading at ABANDONED CHIMNEYS, OUTDOORS or select a topic from the More Reading links shown below.

Suggested citation for this web page

ABANDONED CHIMNEYS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

More Reading

Green link shows where you are in this article series.

...




Frequently Asked Questions (FAQs)

Click to Show or Hide FAQs

Ask a Question or Search InspectApedia

Questions & answers or comments about abandoned chimney detection, inspection, hazards, removal or repair

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

HTML Comment Box is loading comments...

Technical Reviewers & References

Publisher's Google+ Page by Daniel Friedman

Click to Show or Hide Citations & References