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This article describes the antique and modern fireplace inserts used for wood, coal, or pellet fuel heating.
We discuss fireplace inserts and zero-clearance fireplaces, both antique and modern, and their hazards and inspection limitations.
The page top sketch, provided courtesy of Toronto home inspection firm Carson Dunlop Associates illustrates limitations on the visual inspection of fireplace inserts. It does not show proper fireplace insert installation details.
Below we provide photographs of the exploration of the condition of a cast-iron "fireplace" or fireplace grate that was originally intended for burning large chunks of coal, probably soft coal. This installation was found in a home built in Poughkeepsie NY ca 1900 and restored by the author.
Watch out: Because a fireplace insert blocks direct access to the chimney flue from inside a building, the condition of an inaccessible flue is often unknown, and possibly dangerous fire or carbon monoxide hazards could be present. Expert inspection and cleaning are appropriate as at least an annual safety check. Our page top sketch of a typical fireplace insert is provided courtesy of Carson Dunlop & Associates.
Working carefully so as not to damage the ceramic tile fireplace facade and hearth, we removed and disassembled this antique coal burning fireplace insert (burning wood in our photo) to inspect the condition and construction of the chimney flue (above right). The flue was un-damaged, needed cleaning, and was also a bit small for any expanded fuel use in this installation.
Our fireplace photos above show the back and top of this coal burning insert (above left) and the grate assembly (above right).
At below left we show the solid (8" or more) masonry firebox and the opening into a basement ash pit below this fireplace. Our reproduction of an antique fireplace grate insert (below right) was a Dixon's Low-Down Grate. Low fireplace grates were intended for use over an ash pit opening. For upper floor rooms where no ash pit connection was possible, Dixon sold an Elevated Fire Grate.
The installation of low cast iron fire grates over an ash pit was made as shown in this sketch. Dixon's design intended to draw combustion air for the fire from the basement (cellar) or from outside, not from the room being heated - a design considered proper practice in modern homes and required by code in some areas.
Watch out: some older homes used a shared flue among fireplaces and heating appliances on different floors - a practice that is considered unsafe and is prohibited today.
Modern Fireplace Inserts for Burning Wood, Coal, Pellet Fuel
A modern fireplace insert for burning wood is shown at left. You can see why inspecting the chimney from inside is impossible without removing the appliance.
This installation is particularly interesting. If you click to enlarge the photo you can see light colored bricks at the right of the fireplace insert: the installer appears to have bricked the original fireplace opening to better fit the new insert.
Watch out: adding a fireplace insert that moves the fire doors closer to the edge of the hearth reduces fire clearance (for heat or if the doors are open, sparks and coals) between the appliance opening and nearby combustibles or flooring.
The owners have placed a "fireproof rug" in front of this unit - that semi-circular carpet observed on the floor. Is this adequate? Be sure to consult your local fire inspector when installing or converting a fireplace or fuel burning appliance.
Unsafe Fireplace Inserts
By "fireplace insert" we refer to a wood or coal-burning stove designed to be inserted into an existing masonry fireplace opening.
The wood-stove installed in the fireplace at left may work in such a location, but it was not designed as an "insert" - and does not fit the opening of this odd fireplace. In fact not much would fit in this angled firebox.
Placing the feet of the woodstove past the hearth and onto a rug, as well as less than 3' from combustibles, are further fire hazards - this is an unsafe installation.
Do not confuse a fireplace insert woodstove or coalstove with a "zero-clearance" fireplace such as the unit shown here.
Zero-clearance fireplaces are typically steel constructed fireplaces to burn wood or perhaps other fuels such as LP or natural gas in modern homes, usually connected to a metal chimney.
Our photo (left) shows a zero-clearance gas fireplace. Other zero clearance fireplaces burn wood or perhaps other fuels.
The clearance to combustibles is not "zero" but one or more inches, depending on the materials, construction, and manufacturers' instructions.
Watch out: we have found a few zero-clearance fireplaces improperly installed too close to combustibles.
The installer did not understand the purpose of steel clearance-assuring projections welded to the zero-clearance fireplace, and s/he had hammered them flat to "shoe-horn" the zero clearance fireplace into a too-small wood-framed rough opening.
The result was a serious building fire hazard and a building code violation as well.
Our photo of a zero-clearance fireplace from inside the framed opening (left) shows the clearance guards intact next to our ruler.
But inspection showed chimney leaks onto this unit - evidenced by the rust and white stains that can ultimately damage the flue (at upper right) and the fireplace unit, making it unsafe.
Inspecting the Chimney where a Fireplace Insert for Wood or Coal is Installed
In fact it is just about impossible to see the condition of these components and their connections unless the insert is removed or inspected from above using a chimney inspection camera system.
If a woodstove/free-standing fireplace like this were to be used it would probably require at least three feet of clearance from combustibles.
Local codes and fire regulations need to be consulted, and in most jurisdictions, a building permit and safety inspection are required for the installation of a woodstove or similar device.
Abandoning or Removing a Fireplace Insert?
Often when a fireplace insert has been installed, the original fireplace damper has been modified (cut to pass the flue vent connector) or simply removed entirely. If you are discontinuing a fireplace insert, you may need to repair or replace the fireplace damper, or perhaps install a chimney-top damper instead.
Factory-Built or Pre-Fab Fireplace Inspection Checklist
Common Factory-Built Fireplace Defects, Problems, Unsafe Conditions
Chimney & Fireplace Installation: all parts of a factory-built fireplace or chimney must be installed according to instructions provided by the manufacturer and no parts can be damaged to an extent that would impair the function of that part.
Chimney & Fireplace Labels: all parts of a factory-built fireplace or chimney system (except in some jursidictions locally-made covers) must bear labels identifying the parts as listed for use with the fireplace model installed in the building. Examples of labeling issues and even counterfeit labels are at CHIMNEY SHROUD, Decorative
Fireplace air circulators: any louvers, slots or other openings intended to allow air to circulate to and around the fire-box must be clear of obstructions and should not be damaged or have leaks into or out of other building areas or components.
Factory-built fireplace spacers or supports must be in place and not bent, crushed, or damaged. There should be no combustibles that intrude into the fireplace area past the fire clearance distances indicated by the spacers or by the manufacturer's installation instructions.
Floor fire protection: if the fireplace has been installed over a combustible floor a non-combustible safety strip (or other manufacturer specified fire safety and heat protection system) must have been placed underneath the unit and on the floor beneath the hearth extension and the fireplace
Fireplace hearth extension fire protection: the hearth extension must be made of non-combustible materials and of the thickness, depth, and width specified by local building codes & in compliance with the fireplace manufacturer's specifications, OR the hearth extension must be a listed accessory intended for use with the model fireplace installed.
Building insulation installed near the fireplace must be non-combustible and un-faced (e.g. un-faced fiberglass rather than kraft-faced or foil-faced). Where cellulose building insulation is installed it must be shielded and protected from heat that risks combustion, as specified by instructions of the insulation manufacturer and in compliance with local building codes.
Fireplace mounting: the fireplace must be supported and secured or fastened tot he structure or blocked so as to prevent shifting or movement or settlement from its installed position, as specified by the manufacturer.
Mantel, hearth face, other fireplace trim: trim materials at or near the face of the fireplace must comply with both fireplace manufacturer's instructions and local building codes with regard to choice of materials, fire clearance spacing, and fastening methods so as to avoid placing combustible materials too close to a heat source; trim, doors, etc. must be installed without air leaks or gaps as per manufacturer's instructions.
Fireplace modifications: the factory-built fireplace cannot be modified except as permitted by the manufacturer. This includes respecting spacers, trim, mounting locations, and accessories or fire doors.
Fireplace inserts into existing fireplaces or into framed openings may not be installed unless the insert is listed and building-code approved and of course installed according to the manufacturer's instructions. This includes add-on home-heating systems or hydronic systems tying into building heating equipment.
Fireplace chimney & Chimney connections: the chimney should be inspected for proper construction, safe operating condition, etc. as appropriate for the type of chimney materials and construction (masonry, factory-built, etc).
The fireplace owners manual and operating instructions should be provided and should be placed where readily accessible to building occupants. The fireplace identifying tags such as serial number and model number and UL listing or other listing certifications and labels provided by the manufacturer should be intact and left in place as originally installed by the manufacturer.
Additional fireplace safety inspection details are provided at
Inspection checklist warning: No checklist is ever a complete guide to building inspection or diagnosis since no checklist can contain every possible hazard or every clue that suggests a problem.
Therefore do not rely on this or any checklist to assure that your inspection of a chimney is complete. Instead, use this list to suggest additional topics that you otherwise may have omitted from your inspection. The more detailed chimney inspection and repair articles at the links at Related Links and the citations below below suggest further, more-detailed chimney inspection points and procedures.
Adapted from chimney inspection safety sources including these documents cited at REFERENCES
 Baird, David J., C.B.O., "Factory-built Chimney Chase Fires: A case for More Detailed Inspection", Building Standards, March-April 1991, pp. 14-17.
 Purdie, Roger K., "Chimney Fire Safety Bulletin", Vista Fire Protection District, 2001, report of house fire related to the home's metal chimney. Contains advice for chimney * fire safety & sketches of approved and not-code-approved metal chimney tops, caps & crowns. [PDF]
 Fire Inspector Guidebook, [BOOK] 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.
 "Top Ten Chimney (and related) Problems Encountered by One Chimney Sweep," Hudson Valley ASHI education seminar, 3 January 2000, contributed by Bob Hansen, ASHI
 "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.
 "Chimney Inspection Procedures & Codes," Donald V. Cohen, draft, was to be published in the first volume of the 1994 ASHI Technical Journal by D. Friedman
12/27/2014 Anonymous said:
I thought fireplace insert flues at a minimum must extend to the first tile in the chimney.
The diagram shown here [at the top of this page] does not reflect this.
Quite so. If you are referring to the page top sketch, that drawing does not claim to describe a proper stove insert installation; rather it illustrates areas that are not accessible for visual inspection during a home inspection. Thanks for pointing out that the sketch might confuse someone.
A fireplace insert vertical flue vent connector should indeed pass into the first vertical flue tile, subject to further installation specifications provided by the individual fireplace insert manufacturer. Any flue vent connector that connects horizontaly into a masonry chimney flue needs to be flush with the masonry flue interior. Extending an inch past that point is probably ok but extending too far into the flue horizontally is improper and is likely to block draft.
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(Sept 30, 2011) Glenn said:
I have a gas insert and want too build a mantel with a shelve 10-12 inches wide, how high above the insert must the bottom of shelve be.
Glenn the required fire safety clearances are specified in the installatino manual for your gas insert fireplace and will vary among manufacturers. If you give us the brand and model I'll help you find the clearance details.
(Nov 13, 2012) Richard said:
Our house has 8 fireplaces, house built in 1897. We were told they are "coal burning" fireplaces, all masonry, and wanted to know if we should use the cast iron covers, which have a round hole in the top 3/4 part and a "damper" at the bottom. We tried it and it makes the fireplace act like a furnace, but is it safe? Thanks
Question: how to get information about a Superior Model CF-3860 fireplace insert, provided from Superior, The Fireplace Company, Fullerton, California
(Feb 2, 2015) L. Flannery said:
A Superior Model CF-3860 fireplace insert, provided from Superior, The Fireplace Company, Fullerton, California was put in my new home built in 1985 in Edmonton, Alberta Canada. It has been little used and is in excellent shape. Because of our lack of use, I want to install a gas fireplace insert and I am trying to find out whether there are inserts which can be installed into this model without removing it.
The Alberta Fireplace Installation guide says:
"Fireplace inserts must be installed according to their respective listing requirements. Inserts must not be installed in factory-built fireplaces unless the listing specifically allows the combination."
Are there gas inserts which are compatible with this factory-built fireplace? Alternatively, can you direct me to where I can get this question answered.
I'm doubtful but can't offer a specific gas heating product for the fireplace insert you cite.
I'd start by giving the company a call to see what they themselves recommend for their product line.
Contact the Superior Fireplace Company,
4325 Artesia Ave., Fullerton, CA 92833 USA
Tel: (800) 731-8101
Email : E-mail this company
Web Site : www.superiorfireplace.com
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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: email@example.com
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 firstname.lastname@example.org
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
NFPA 211 - 3-1.10 - Relining guide for chimneys
NFPA 211 - 3-2 - Construction of Masonry Chimneys
NFPA 211 - 3-3 - Termination Height for chimneys
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
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.
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: email@example.com. 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