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.
Inspection & Assessment of Abandoned Chimneys in buildings
A 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.
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.
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.
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.
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.
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Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Mr. Cramer serves on the ASHI Home Inspection Standards. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com
John Cranor is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to InspectApedia.com in several technical areas such as plumbing and appliances (dryer vents). Contact Mr. Cranor at 804-747-7747 or by Email: firstname.lastname@example.org
Home Inspection Education Home Study Courses - ASHI@Home Training 10-course program. Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Home Reference Book, a reference & inspection report product for building owners & inspectors. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
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The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones.
Thanks to Luke Barnes for suggesting that we add text regarding the hazards of shared chimney flues. USMA - Sept. 2008.
Arlene Puentes, an ASHI member and a licensed home inspector in Kingston, NY, and has served on ASHI national committees as well as HVASHI Chapter President. Ms. Puentes can be contacted at email@example.com
Roger Hankeyis principal of Hankey and Brown home inspectors, Eden Prairie, MN, technical review by Roger Hankey, prior chairman, Standards Committee, American Society of Home Inspectors - ASHI. 952 829-0044 - hankeyandbrown.com
NFPA #211-3.1 1988 -
Specific to chimneys, fireplaces, vents and solid fuel burning appliances.
NFPA # 54-7.1 1992 -
Specific to venting of equipment with fan-assisted combustion systems.
Gas Appliance Manufacturers' Association has prepared venting tables for
Category I draft hood equipped central furnaces as well as fan-assisted
combustion system central furnaces.
National Fuel Gas Code, an American National Standard, 4th ed. 1988 (newer edition is available) Secretariats, American Gas Association (AGA), 1515 Wilson Blvd., Arlington VA22209, and National Fire Protection Association (NFPA), Batterymarch Park, Quincy MA 02269. ANSI Z223.1-1988 - NFPA 54-1988. WARNING: be sure to check clearances and other safety guidelines in the latest edition of these standards.
Fire Inspector Guidebook, A Correlation of Fire Safety Requirements Contained in the 1987 BOCA National Codes, (newer edition available), Building Officials and Code Administrators International, Inc. (BOCA), Country Club HIlls, IL 60478 312-799-2300 4th ed. Note: this document is reissued every four years. Be sure to obtain the latest edition.
Uniform Mechanical Code - UMC 1991, Sec 913 (a.) Masonry Chimneys,
refers to Chapters 23, 29, and 37 of the Building Code.
New York 1984 Uniform Fire
Prevention and Building Code, Article 10, Heating, Ventilating, and Air Conditioning Requirements
New York 1979 Uniform Fire Prevention & Building Code, The "requirement" for 8" of solid masonry OR for use of a
flue liner was listed in the One and Two Family Dwelling Code for New
York, in 1979, in Chapter 9, Chimneys and Fireplaces, New York 1979
Building and Fire Prevention Code:
"Top Ten Chimney (and related) Problems Encountered by One Chimney Sweep," Hudson Valley ASHI education seminar, 3 January 2000, contributed by Bob Hansen, ASHI
"Rooftop View Turns to Darkness," Martine Costello, Josh Kovner, New Haven Register, 12 May 1992 p. 11: Catherine Murphy was sunning on a building roof when a chimney collapsed; she fell into and was trapped inside the chimney until rescued by emergency workers.
"Chimneys and Vents," Mark J. Reinmiller, P.E., ASHI Technical Journal, Vol. 1 No. 2 July 1991 p. 34-38.
"Chimney Inspection Procedures & Codes," Donald V. Cohen was to be published in the first volume of the 1994 ASHI Technical Journal by D. Friedman, then editor/publisher of that publication. The production of the ASHI Technical Journal and future editions was cancelled by ASHI President Patrick Porzio. Some of the content of Mr. Cohen's original submission has been included in this more complete chimney inspection article: InspectAPedia.com/chimneys/Chimney_Inspection_Repair.htm. Copies of earlier editions of the ASHI Technical Journal are available from ASHI, the American Society of Home Inspectors.
Natural Gas Weekly Update: http://tonto.eia.doe.gov/oog/info/ngw/ngupdate.asp Official Energy Statistics from the U.S. Government
US Energy Administration: Electrical Energy Costs http://www.eia.doe.gov/fuelelectric.html
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
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Carson Dunlop, Associates, Toronto, have provided us with (and we recommend) Carson Dunlop Weldon & Associates' Technical Reference Guide to manufacturer's model and serial number information for heating and cooling equipment Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.