Repair Methods for Ongoing Chimney Movement, Leaning Chimneys
CHIMNEY LEANING, REPAIR OPTIONS - CONTENTS: List of repair alternatives for chimney separation or movement that is ongoing and a major problem,Leaning, separated or cracked chimneys; missing chimney supports
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How to fix chimney separation or movement:
This article describes the common repair methods used to handle a chimney which is leaning, cracked, or separating from a building. We outline common repair methods used to stabilize loose or leaning chimneys. These articles on chimneys and chimney safety provide detailed suggestions describing how to perform a thorough visual inspection of chimneys for safety and other defects. Chimney inspection methods and chimney repair methods are also discussed.
As we cited earlier at Chimney Movement is Ongoing - Evidence, sometimes
we see a chimney that has been "repaired" in this manner several times, with several
generations of concrete or caulk or wood trim strips.
Our closeup photo at the top of this page showed a wide concrete patch between a chimney and the building. Often we see thick build-up of roofing mastic where a chimney has moved at the edge of a building roof.
In both photos below, a wide metal strip has been fabricated to cover the gap that has opened between the chimney and the building (below right) and a heavy metal strap has attempted to "bolt" the chimney to the home (below left, also visible at the upper chimney section (below right).
[Click to enlarge any image]
Just below are additional photographs of a masonry chimney with significant separation and leaning away from the building.
Why is this chimney strapping repair alone probably inadequate?
If the chimney is settling because of an inadequate footing, it is unlikely that this repair will succeed. On occasion we've seen the mass of a heavy chimney actually pull the building wall along with it as it settled and tipped further.
The chimney flue interior is likely to be damaged and unsafe
The fireplace box, hearth, and support are likely to be damaged and unsafe
What could have been done to repair the chimney shown above?
Confirm that the defect is due to a bad chimney footing, stabilize the footing using slab-jacking or helical piers
Re-line the damaged chimney flue
Align, stabilize, and repair cracks in the fireplace box and hearth
Remove the chimney entirely, then construct a new chimney on a proper footing
Abandon the chimney entirely, stabilize and leave it in place, provide alternative chimneys to vent the home heating appliances using a manufactured chimney elsewhere on the building
Abandon the chimney entirely, convert the heating boiler or furnace to a high-efficiency direct-vent unit.
Which of these alternatives makes most sense depends on other factors such as the condition of the heating equipment and the desire to have a traditional masonry fireplace.
A Summary of Leaning Chimney Repair Methods
Strapping a masonry chimney to the building in an attempt to stabilize a tipping or leaning chimney it is unlikely to work, especially if the root cause of chimney movement is an inadequate or tipping chimney foundation. The total weight or mass of a masonry chimney is enormous.
Trying to hold this weight in place by strapping the flue to the building structure risks bending or moving the structural wall in many instances. (If a chimney has a sound footing or a soundly-repaired footing and is to be tied to the building as a retrofit repair, the building tie-in may need to pass through the building rather than just being connected to the building wall abutting the chimney.)
It is normal to tie a masonry chimney to the building to prevent movement. Those ties, if present, are likely to be hidden between the chimney side facing the building and the building wall itself. That lateral chimney support stabilizes a chimney that has a sound footing. But lateral support cannot normally stabilize a chimney whose footing is missing or tipping.
Chimney reconstruction: if the chimney has moved more than a very small amount, perhaps less than 3/16", some chimney repair companies may suggest that the chimney should be disassembled and rebuilt correctly. That is because they are worried that internal cracks in the masonry flue have made the chimney a flue gas and fire hazard.
Certainly if a chimney has moved significantly away from a building it is almost certainly dangerous, risking a building fire and flue gas leakage.
Chimney top repairs: if the damage to a chimney top or flue is confined to the area from the roof surface up to the chimney top, it is common to remove and rebuild the chimney in that location. Make sure that the new chimney top has a proper chimney cap and rain cap as well as an expansion joint/seal around the masonry flue at the chimney cap. See CHIMNEY REPAIRS, TOP & CLAY FLUE TILE for details.
Chimney foundation repairs: If a leaning chimney is relatively un-damaged, and if the movement is traced to ongoing chimney foundation settlement, it might be possible to use helical piers, driven pins, or other foundation repair methods to repair the chimney.
Flue relining a moving chimney: Some chimney repair companies may suggest stabilizing a chimney flue that has moved, followed by installation of a flue liner in order to assure that the flue is fire and gas safe. See Re-Lining Choices for Masonry Chimneys.
Fireplace movement repairs: If you are considering this repair be sure that your mason and chimney company inspect any fireplaces carefully. we have observed movement and cracking in the firebox which made the fireplace and hearth serious fire hazards themselves, independent of questions about the safety of the chimney flue. We have observed fireplace hearth settlement repairs obtained by jacking the settled hearth from below, combined with careful inspection and sealing.
If the fireplace itself has settled or tipped, typically also causing chimney separation, it may be possible to add support and jack the fireplace base level using slab jacking or foundation settlement repair methods. However the risk of this approach is leaving a damaged and unsafe fireplace or chimney flue in place. Very thorough and expert inspection is required and chimney relining may also be needed. The cost of all of those steps may be competitive with reconstruction of the fireplace and chimney. See Fireplace Safety Hazards.
Metal chimney repairs: if the chimney is a factory built or metal chimney and flue, most often the proper repair is complete replacement of damaged or rusted chimney parts. An exception, of course, is the replacement of a damaged or missing chimney rain cap or above-roof components.
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Questions & answers or comments about how leaning, separated-from-building, or moving or cracked chimneys are repaired.
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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
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.php. 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
Ceramic Roofware, Hans Van Lemmen, Shire Library, 2008, ISBN-13: 978-0747805694 - Brick chimneys, chimney-pots and roof and ridge tiles have been a feature of the roofs of a wide range of buildings since the late Middle Ages. In the first instance this ceramic roofware was functional - to make the roof weatherproof and to provide an outlet for smoke - but it could also be very decorative.
The practical and ornamental aspects of ceramic roofware can still be seen throughout Britain, particularly on buildings of the Victorian and Edwardian periods. Not only do these often have ornate chimneys and roof tiles but they may also feature ornamental sculptures or highly decorative gable ends. This book charts the history of ceramic roofware from the Middle Ages to the present day, highlighting both practical and decorative applications, and giving information about manufacturers and on the styles and techniques of production and decoration.
Hans van Lemmen is an established author on the history of tiles and has lectured on the subject in Britain and elsewhere. He is founder member and presently publications editor of the British Tiles and Architectural Ceramics Society. Available at the InspectAPedia Bookstore.
Chimney & Stack Inspection Guidelines, American Society of Civil Engineers, 2003 - These guidelines address the inspection of chimneys and stacks. Each guideline assists owners in determining what level of inspection is appropriate to a particular chimney and provides common criteria so that all parties involved have a clear understanding of the scope of the inspection and the end product required. Each chimney or stack is a unique structure, subject to both aggressive operating and natural environments, and degradation over time. Such degradation may be managed via a prudent inspection program followed by maintenance work on any equipment or structure determined to be in need of attention. Sample inspection report specifications, sample field inspection data forms, and an example of a developed plan of a concrete chimney are included in the guidelines. This book provides a valuable guidance tool for chimney and stack inspections and also offers a set of references for these particular inspections.
NFPA 211 - 3-4 - Clearance from Combustible Material
NFPA 54 - 7-1 - Venting of Equipment into chimneys
Brick Institute of America - Flashing Chimneys
Brick Institute of America - Proper Chimney Crowns
Brick Institute of America - Moisture Resistance of Brick
American Gas Association - New Vent Sizing Tables
Chimney Safety Institute of America - Chimney Fires: Causes, Effects, Evaluation
National Chimney Sweep Guild - Yellow Pages of Suppliers
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: firstname.lastname@example.org. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
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.
TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates 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.
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.
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 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