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Type B Gas Vent (C) Daniel Friedman Type B-Vents for Gas Fired Appliances

Specifications for use of Type B gas vents, unsafe Type B vents, B-Vent fire clearances

Metal B-Vent flue installation requirements & inspection suggestions.

This article describes B-vent metal chimneys used for gas-fired appliances. What are Type B vents and where are they used? B-vents for gas fired appliances are explained. We include photos of B-vent markings & labels for identification.

We give chimney cap requirements for B-vents and we discuss fire safety, fire clearances, and other gas appliance venting details for metal B-vent chimneys

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

- Daniel Friedman, Publisher/Editor/Author - See WHO ARE WE?

Type B-Vents for Gas Fired Appliances

Type B Vent (C) Carson Dunlop Associates

Type B-vents are double-walled metal chimneys/flues and can be used only with listed, draft-hood equipped gas appliances.

Type B gas vents such as the Ameri-Vent™ are permitted for venting gas-fired appliances and have their own set of combustible clearance and installation specifications.

 

A Type B vent is intended for relatively low-heat applications.

B-vents are not permitted for use with incinerators and are not intended for use with appliances burning anything other than LP or natural gas.

Watch out: B-Vents are not for use with fireplaces, woodstoves, or oil-fired equipment.

 

As you see in our close-up photo below, a rated or UL-listed type B-vent chimney will usually be clearly labeled.

The B-vent also requires that its own special chimney cap be installed.

If the cap is lost, do not substitute something not recommended by the manufacturer or the chimney may be unsafe.

Watch out:  also for a "home made" B-vent using aluminum or clothes dryer venting products.

Those are not intended for venting gas appliances and would be unsafe in such use.

Type B Gas Vent (C) Daniel Friedman

B-Vent Chimney Outdoor Temperature Limits

Question: B-Vent outdoor temperature limits

Can B-Vent be used as an exterior chimney in New York where temps reach 10 below? - Edward J Foley 2022/04/28

This Q&A were posted originally

at TYPE B-VENT ROOFTOP CLEARANCE

Moderator reply: recommendation: insulated chimney chase for tall outdoor B-Vent chimneys in very cold climates

NO, that is, probably not without an enclosing and insulated chimney chase. Also check with your local building department about what's permitted and safe where you live.

New York 2020 Fuel Gas Code (based on the 2018 International Fuel Gas Code) states the following:

503.7.2 Cold Climate

Uninsulated single-wall metal pipe shall not be used outdoors for venting appliances in regions where the 99-percent winter design temperature is below 32°F (0°C).

504.2.9 Chimney and vent locations.

Tables 504.2(1), 504.2(2), 504.2(3), 504.2(4) and 504.2(5) shall be used only for chimneys and vents not exposed to the outdoors below the roof line.

A Type B vent or listed chimney lining system passing through an unused masonry chimney flue shall not be considered to be exposed to the outdoors.

Where vents extend outdoors above the roof more than 5 feet (1524 mm) higher than required by Figure 503.6.5, and where vents terminate in accordance with Section 503.6.5, Item 2, the outdoor portion of the vent shall be enclosed as required by this section for vents not considered to be exposed to the outdoors or such venting system shall be engineered.

A Type B vent shall not be considered to be exposed to the outdoors where it passes through an unventilated enclosure or chase insulated to a value of not less than R8.

Details:

While it's often permissible to extend the B-vent chimney from the building interior to its exterior, and while we see that illustrated in typical installation instructions, that's not the end of the question about exposure of a B-vent to low outdoor temperatures.

Watch out: B-vent chimney manufacturers may provide different instructions for their products, some permitting the use of the B-vent outside with no chimney chase and others requiring that the chimney be enclosed in a chaseway until it reaches the rooftop height.

The concern - which I am guessing you suspect as well - is that at very low outdoor temperatures the draft inside the B-vent chimney flue could be insufficient.

The result risks production and release of fatal carbon monoxide gas in the building served by the heating equipment thus vented.

There could also be a problem of corrosion or equipment damage from high levels of condensate forming in the very cold flue, or even frost formation near the chimney top, blocking or obstructing the venting of flue gases in extremely cold climates.

In reading literature about type B Vent chimneys we often find manufacturers or literature noting that a chimney chase may be needed in cold climates to assure adequate and safe draft.

A Type B-vent chimney receives incoming flue gases in the 400 - 480°F (249°C) - that's the temperature of combustion gases entering the chimney

The B-vent's exterior surface is designed to not exceed 90°F - thus meeting fire clearance and safety code requirements, but it does so with an air space between an inner and outer metal flue.

Contrast that with other more-insulated chimneys such as Class-A Chimneys whose construction involves an insulator

see CLASS A CHIMNEYS, MetalBestos™

Building Code Requirements for Outdoor Use of B-Vent Chimneys

Excerpt from the New York State Code

[The underscore emphasis is ours - Ed.] - Note that these are excerpts, not the entire code.

503.7.2 [Single-Wall Metal Chimneys in ] Cold Climate

Uninsulated single-wall metal pipe shall not be used outdoors for venting appliances in regions where the 99-percent winter design temperature is below 32°F (0°C).

503.10.2.2 Vent Connectors Located in Unconditioned Areas

Where the vent connector used for an appliance having a draft hood or a Category I appliance is located in or passes through attics, crawl spaces or other unconditioned spaces, that portion of the vent connector shall be listed Type B, Type L or listed vent material having equivalent insulation properties.

Exception:

Single-wall metal pipe located within the exterior walls of the building in areas having a local 99-percent winter design temperature of 5°F (-15°C) or higher shall be permitted to be used in unconditioned spaces other than attics and crawl spaces.

504.2.9 [B-Vent ] Chimney and vent locations.

Tables 504.2(1), 504.2(2), 504.2(3), 504.2(4) and 504.2(5) shall be used only for chimneys and vents not exposed to the outdoors below the roof line.

[Note: for Type B-Vent chimneys see TABLE 504.3(1) TYPE B DOUBLE-WALL VENT - Ed]

A Type B vent or listed chimney lining system passing through an unused masonry chimney flue shall not be considered to be exposed to the outdoors.

Where vents extend outdoors above the roof more than 5 feet (1524 mm) higher than required by Figure 503.6.5, and where vents terminate in accordance with Section 503.6.5, Item 2, the outdoor portion of the vent shall be enclosed as required by this section for vents not considered to be exposed to the outdoors or such venting system shall be engineered.

A Type B vent shall not be considered to be exposed to the outdoors where it passes through an unventilated enclosure or chase insulated to a value of not less than R8.

Table 504.2(3) in combination with Table 504.2(6) shall be used for clay-tile-lined exterior masonry chimneys, provided that all of the following are met:

1. Vent connector is a Type B double wall.

2. Vent connector length is limited to 11/2 feet for each inch (18 mm per mm) of vent connector diameter.

3. The appliance is draft hood equipped.

4. The input rating is less than the maximum capacity given by Table 504.2(3).

5. For a water heater, the outdoor design temperature is not less than 5°F (-15°C).

6. For a space-heating appliance, the input rating is greater than the minimum capacity given by Table 504.2(6).

Source: 2020 Fuel Gas Code of new York State, based on the 2018 Inernational Fuel Gas Code, retrieved 2022/04/28 original source: https://codes.iccsafe.org/s/NYSFGC2020P1/chapter-5-chimneys-and-vents/NYSFGC2020P1-Ch05-Sec504.2.9

Note: The Fuel Gas Code Table 504.2 Application of Single-Appliance Vent Tables 504.2(1) Through 504.2(6)

provides required chimney heights for vents of various diameters given various appliance input BTUH rating (in thousands of BTUs/Hour) .

Type B Vent Installation Errors to Avoid

Get the Metal Chimney Sections Right-Way Up

Metal chimney assemblies, including Type B-Vents Includes a "right way up" which you can see Amerivent stamps or embosses right into the steel surface as well as marking it again on a printed label, giving us two chances to get it right.

Type B gas vent installation specifications (C) Daniel Friedman

Here is a close-up of the vent label: note the "up" arrow.

Type B gas vent installation specifications (C) Daniel Friedman

At below left you can see the Type B gas vent installed "right way up". Why is this important?

Use Type B Gas Vents Only On Gas Fired Equipment - not with other fuels

Type B gas vents are not to be used with incinerators or with appliances burning solid or liquid fuels. The gas vent is correctly installed here on a gas fired heater.

Type B gas vent installation specifications (C) Daniel Friedman

Below, Ameri-Vent's Type B gas vent label makes plain that the vent is intended only for use with listed, draft-hood-equipped gas appliances.

Type B gas vent installation specifications (C) Daniel Friedman

Stupid Home-Made Gas Vent Tricks

Besides choosing the right chimney material for the appliance it is to vent, a safe installation follows applicable building codes and standards.

Type B gas vent unsafe installation (C) Daniel Friedman

But the Type B vent manufacturers make a concerted effort to get their products installed correctly and safely even by fellows who prefer to use the instructions to kneel upon.

Well what can I say about this photo pair above and below ?

This creative "gas vent" and home made "chimney cap" had nothing right and nothing safe about it.

It is worth taking a look at all chimneys from time to time - perhaps to notice that a cap has been lost (below left) or other damage has occurred.

Type B gas vent unsafe installation (C) Daniel Friedman

Below: a damaged DIY gas vent with no cap.

Type B gas vent unsafe installation (C) Daniel Friedman

In our photo below that aluminum, horizontal pipe near the building corner is venting a gas fired water heater. Or is it? At the stone wall we see a second larger B-type gas vent for the heating system.

Type B gas vent unsafe installation (C) Daniel Friedman

Type B Vent Improperly Used as a Direct Vent

At B-VENT IMPROPER USE as DIRECT VENT we illustrate an installation of a gas fired room heater designed to be vented using a B-Vent chimney but where the owner terminated teh B-Vent at the sidewall as if it were a Direct Vent applince.

That installation is wrong and dangerous.

in our separate article on GAS APPLIANCE / HEATER DIRECT VENT CLEARANCES

Type B Vent Chimney Labels & Identification

Our photos below show the common embossed and printed labels that identify Type B Gas vents.

Type B gas vent installation specifications (C) Daniel Friedman

In the photo just above and just below are labels and the UL listing mark on a Type B Gas Vent produced by Amerivent.

Type B gas vent installation specifications (C) Daniel Friedman

Below is a similar product produced by the Canadian manufacturer Selkirk.

Selkirk B-Vent (C) Daniel Friedman

Below I'm holding a new section of Selkirk's Type B gas vent to show its double-wall construction.

Selkirk B-Vent (C) Daniel Friedman

L-Vents vs B-Vents - What's the Difference?

As we state at TYPE L VENT CHIMNEYS, it can be confusing distinguishing between L-Vent chimneys and B-Vent chimneys, in part because the same components may be used in both heat venting range installations.

Type L-Vents conform to UL 641 and are intended for higher temperature applications such as venting oil fired heating equipment. A Type-L vent can also be used for venting a gas appliance as explained below.

Type B-Vents are intended for lower temperature gas fired heating equipment applications and should not be used with other fuels (such as home heating oil).

Describing their model DFS L-Vent/ Type B Gas Vent installation procedures, Selkirk Corporation, a producer of metal chimneys and vents, offers these details:

Type L-Vent is designed for venting approved oil or gas appliances producing draft hood flue gases not exceeding a temperature of 570ºF (299ºC).

Type B Gas vent is designed for venting approved gas appliances equipped with draft hoods and other Listed gas appliances specified for use with Type B Gas vent which produce flue gases not exceeding 480°F (249°C).

Note: some specific B-vent manufacturers may set a different maximum flue gas temperature. For example see Hart and Cooley's documentation given below and in which the company states

"Type B Gas Vent is designed for negative pressure applications and flue gas temperatures not exceeding 400°F above ambient for Category I appliances.".

Minimum clearance between the vent and combustible materials is 3 inches for L-Vent and 1 inch for Type B gas vent.

L-Vent or B-Vent that extends through any story above that on which the connected appliance is located is to be provided with enclosures having a fire resistance rating equal to or greater than that of the floor or roof assemblies through which they pass.

Framing dimensions of enclosures and at joist or rafter levels shall be a minimum of 6" larger than the outside of the vent for L-Vent and 2” larger for B-Vent.

Near the vent base, post a notice of the type of appliance for which the DFS installation to combustibles is installed. If installed at 1” airspace, it is limited to B-Vent (gas) only.

If it is installed at 3” airspace, it it may be used with oil (as an LVent) or gas (as a B-Vent).

 

Chimney & Vent Codes & Installation Manuals

3” to 12” inner and outer pipe curled together as an integral unit.

14” - 30” sizes have a snap-lock coupling system.

Unique locking band provides 360° turning radius of the pipe and fittings.

Locking band slides over tabs easily, locks firmly without twisting. Locking tabs hold pipe securely together, can be easily unlocked.

Reinforced ends– curled bead on end of outer pipe for rigidity and strength.

Deep Locking Groove assures solid joint and secure lock.

Corrosion-resistant aluminum inner wall for rapid warm-up.

Galvanized steel outer pipe for maximum protection.

Positive Stop—provides proper alignment and positive fit for mating end of pipe or fitting

Hart & Cooley, Inc., CHIMNEY & VENTING PRODUCT WARRANTY [PDF] HART & COOLEY, INC 5030 Corporate Exchange Blvd. SE Grand Rapids, Michigan 49512 ATTN: WARRANTY CLAIMS 1.800.433.6341, Fax: 1.800.223.8461 www.hartandcooley.com - OR - AMERICAN METAL PRODUCTS 5030 Corporate Exchange Blvd SE Grand Rapids, Michigan 49512 ATTN: WARRANTY CLAIMS 1.800.423.4270, Fax: 1.800.626.3825 www.ameri-vent.com

Ceiling, Wall & Wall Clearances for B-Vent "flue pipes"

Type B Chimney Fire Clearance Details have moved to a separate article now found

at TYPE B-VENT CEILING FLOOR WALL CLEARANCES

Type B Gas Vent Rooftop Chimney Height & Clearances

This article has moved. Please see detailed B-vent chimney rooftop clearance table

at TYPE B-VENT ROOFTOP CLEARANCE

Also see CHIMNEY HEIGHT & CLEARANCE CODE - separate article that compares the B-vent with other chimney types.

Table of Type B-Vent Rooftop Clearance Requirements

The 1992 Vent Sizing Tables require that all Type B gas vents terminate above the roof with a listed cap or listed roof assembly in accordance with the manufacturer's instructions.

However B-vent chimney caps 12" and smaller may terminate a distance above the roof if 8 feet or more away from a vertical surface as given in this table:

TYPE B-VENT ROOFTOP CLEARANCE

...


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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

Do I need to build a chimney chase to enclose a B-vent chimney routed outside of my building?

I want to put an atmospheric vented 40 gallon gas water heater in the utility room on the main floor of a 2 story house. It will be located against an outside wall.

Double wall Type B vent pipe will run 2 feet vertical from the draft hood into a 90 degree elbow.

Then 16 inch horizontal through a wall thimble and into another 90 degree elbow.

Then 15 feet vertical up the outside of the house through the eve terminating 2 feet above the highest part of the roof within 12 feet.

My question is:

Can I leave the B vent going up the outside of the house in the open or does it have to be enclosed in a chase?
Rural Oregon location - On 2020-12-04 by Jim

Answer by (mod) -

Jim

Short answer: yes, you will want to enclose your B-vent in a chimney chase, especially as your building is in a cool or cold climate.

From the INDEX to RELATED ARTICLES found at the end of this article we list information about B-vent chimneys starting at this page:

TYPE B-VENT CHIMNEYS - https://inspectapedia.com/chimneys/B-Vent-Chimneys.php

that describes B-vent installation procedures and mistakes to avoid, and that provides links to PDF copies of B-vent installation instructions from several manufacturers.

Of course you'll want to check the installation instructions for your specific water heater and the B-vent that you purchase to use with it.

Using Selkirk's IO manual (from that web page cited above) as an example, you'll see that the company expects the chimney to be exposed outdoors and has both safety and durability suggestions of which I include examples below:

Vent Location: enclose exterior portions of B-vents

Selkirk Type B Gas Vents are recommended to be installed within the heated portion of the structure whenever possible.

If an exterior location is necessary it is highlyrecommended to enclose exposed portions (especially in cold climates) to reduce heat loss which may in turn lead to poor draft and/ or condensation/icing problems.

Safety (under "Vent Location"): provide adequate room air supply

Appliances served by an exterior gas vent must have an air supply to the appliance room adequate to balance indoor and outdoor pressures.

Otherwise, “stack action” of the heated building can cause reverse venting action when the appliance is off, or operating on its pilot.

To prolong the life and appearance of the galvanized steel outer casing

and other parts of Selkirk Gas Vents located outdoors, use proper painting procedure at time of installation. Remove oil and dirt with a solvent.

Paint first with a good quality zinc primer or other primer recommended for use on galvanized steel.

Next apply an appropriate finish coat.

Ordinary house paints applied directly to galvanized steel may not adhere well and do not prevent underfilm corrosion which leads to paint loosening and peeling.


Do I need a draft hood on my new Rheem gas fired water heater?

Draft hood atop a Rheem gas fueled water heater or geyser at Inspectapedia.comI am replacing the Bradford White model mims40t6ln gas water heater in my mobile home with a Rheem gas water heater made for manufactured homes.

My existing hot water heater doesn't have a vent draft hood connecting to the double wall exhaust vent but the new one comes with one.

Do I install it with the new one?

The water heater is in a utility closet accessible on the outside of my house On 2020-05-09 by Tony

Answer by (mod) - Gas Fueled water heater draft hood requirement MAY be required - model dependent; diret vent water heaters don't use a draft hood; others do use one.

Tony

If you're asking about the vent hood that's normally right at the top of the gas-fueled water heater, that device is required for safe operation and proper draft regulation.

You can see the draft hood atop the Rheem manufactured home water heater in this snapshot

Watch out: on most gas fueled water heater the draft hood is required for safe operation. But we note that installation instructions for some mobile home gas fueled water heaters such as the Rheem side inlet direct vent gas water heater illustrated below (vent colored in orange) do NOT show a conventional draft hood used on that water heater's installation.

Source: Rheem Side Inlet Direct Vent Gas Water Heaters for Manufactured Housing [PDF] Rheem Corp. , local copy filed as Rheem-Direct-Vent-Manufactured-Home-Water-Heater-Manual.pdf

Note to the illulstration below: This water heater complies with Section 3280.707(d) (2) of H.U.D. Mobile Home Construction and Safety Standards.

 

Can I connect an Amerivent metal chimney to a Selkirk Metal Chimney or Vent Section?

Can I use an Amerivent pipe to connect to a chimney byt Selkirk? Will they lock together? On 2020-03-18 by Carl

Answer by (mod) - NO

Thanks for the question about interconnecting Amerivent and Selkirk metal chimney parts, Carl.

As you can see from the example photo below, the chimney connections are different- stick with a single manufacturer for safety.



Does my B-Vent Chimney really need a chimney cap?

The wind apparantly blew my Type B Gas vent cap(0ld 3" made by Americap) off as I found it on the ground. I am not sure which vent pipe it came off. Does this present a problem as we have been having quite a bit of rain lately? On 2019-02-03 by John Ulman

Answer by (mod) - Yes

There are several safety concerns in the situation you described including water damage to the heating equipment that could make it unsafe, downdrafts that could cause improper venting and risk fatal carbon monoxide poisoning, and ultimately rust damage to the equipment or flue.

I should be trivial to see which vent the rain cap belongs on by inspecting on the roof to see which one is missing. If you can't access your roof safely yourself it's time to hire mechanic with a ladder.


Do I have to center a B-vent between two rafters exactly?

I have my B-Vent securely anchored to a rafter (maintaining a 1" clearance using AmeriVent Vent Pipe Hangers).

Should I relocate it directly between 2 rafters instead before I have a roofer cut the hole and install flashing, extension pipe, storm collar, and cap? On 2018-11-11 by Scott

Reply by (mod) - no

Scott

As long as you are meeting the B-vent manufacturer's fire clearance distances including from the nearest rafter, I don't know of any reason that it needs to exit the roof precisely in the middle between two rafters.

However looking at your photo I see a few items worth mentioning:

1. You will need to remove the B-vent up close to the roof underside or otherwise protect it from both damage and from sawdust and roof debris that otherwise will fall into the vent during the cuttting of the roof exit opening.

2. Your roof decking looks liike two or more generations of pine boards, possibly on an older home that originally was roofed with wood shingles. Or were those nailers overlaid with plywood? I can't quite make that out.

In any case, if the roof opening cuts through one of the original roof nailer boards, you may need to add blocking to support free end of the board.

3. The roof framing looks a bit hodge-podge to me with incomplete rafters tacked together to the left of your B-vent, abutting what may have originally been a lower ridge board with almost no visible nails - the connections could be questionable.

If I were a roofer asked to work on this roof from above, and if I had any experience with old roofs (and workers falling through them or of later being blamed for subsequent roof failures) I would want to inspect the condition of the roof framing and support from the attic side before going on the roof itself. I might then have some suggstions.

...

Continue reading at TYPE B-VENT CEILING FLOOR WALL CLEARANCES or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see TYPE B-VENT CHIMNEY FAQs - questions & answers posted originally at this page

Or see these

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Suggested citation for this web page

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


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Citations & References

In addition to any citations in the article above, a full list is available on request.

  • Technical Reviewers/Commenters include
  • 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 [Website: /www.house-whisperer.com ] 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 804-873-8534 or by Email: johncranor@verizon.net
  • Thanks to Luke Barnes for suggesting that we add text regarding the hazards of shared chimney flues. USMA - Sept. 2008.
  • Arlene Puentes [Website: www.octoberhome.com ] , 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 ap@octoberhome.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: Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances, (2024) at the NFPA Bookstore, (Older NFPA editions and standards are found at the same bookstore)
  • 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.
  • GAMA, VENTING TABLES, CATGORY I CENTRAL FURNACES [PDF] (1990 & 2000) Gas Appliance Manufacturers' Association,, includes also fan-assisted combustion system central furnaces.

    SPECIAL METAL-FAB UPDATE AS OF MARCH 2000 The venting tables within this booklet have now been included in the National Fuel Gas Code (NFPA 54/ANSI Z223.1-1999). That code may also be used to size venting systems for drafthood equipped central furnaces or for fan-assisted combustion system central furnaces.

    This booklet contains new venting tables designed specifically for use with Category I central furnaces.

    These tables are unique, in that, industry wide venting tables now exist for fan-assisted combustion system central furnaces. Venting tables for these types of appliances are not contained in the National Fuel Gas Code (NFPA 54/ANSI Z223.1-1988).

    All requirements contained in this booklet apply to both Category I drafthood equipped central furnaces as well as fan-assisted combustion system central furnaces. At no time should a venting system for a listed Category II, III, or IV central furnace be sized with these tables.

    The National Fuel Gas Code (NFPA 54/ANSI Z223.1-1988) may also be used to size venting systems for drafthood equipped central furnaces.

    However, at this time, the National Fuel Gas Code does not include alternate sizing methods for fan-assisted combustion systems.

    Therefore, until engineering data is developed to allow alternate sizing methods for Category I fanassisted central furnaces, the enclosed venting tables must be used for fan-assisted combustion system central furnaces.

    These tables apply to venting single appliances and common venting multiple appliances in both metal and masonry chimneys.
  • 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.
  • ICC, Fire Inspector Guide Based on the 2021 International Fire Code [ICC Digital Subscription] International Code Council
  • 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
  • Chimney Inspection Checklist, Carson Dunlop, Associates, Toronto, Ontario
  • "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.
  • "Chimneys and Vents", 789 CMR 68.00 Massachusetts Building Code, web search 10/15/2010, original source:
    http://www.mass.gov/Eeops/docs/dps/780%20CMR/780068.pdf 03/23/2007
    780 CMR: STATE BOARD OF BUILDING REGULATIONS AND STANDARDS THE MASSACHUSETTS STATE BUILDING CODE - quoting:
    6801.11 Multiple-Appliance Venting Systems. Two or more listed and labeled fossil fuel-fired appliances shall not be connected to a common natural draft venting system unless permitted per applicable requirements of 248 CMR or 527 CMR. For solid fuel-burning appliances, see 780 CMR 6801.12.
  • Chimneys and Vents, Chapter 18, M1801,model building code - [on file as Code_Chim_Res_C_18.pdf] - widely used by U.S. & Canadian Municipalities,
  • "Model DFS L-Vent / Type B Gas Vent Installation Instructions", Selkirk Corporation, 5030 Corporate Exchange Blvd., Grand Rapids MI 49512, Tel: 800-433-6341 & Selkirk Canada Corporation, PO Box 526, Depot 1, Hamilton ON L8L 7X6, 888-735-5475, web search 10/15/2010, original source: www.mass.gov/Eeops/docs/dps/780%20CMR/780068.pdf
  • "Type L Temperature Venting Systems [on file as L_Vent_Metal_Fab.pdf] - ", Installation and Maintenance Instructions, Metal-Fab Inc., PO Box 1138, Sichita KS 67201, 316-943-2351, Email: info@mtl-fabinc.com website: www.mtl-fabinc.com
  • "Type L Vent Vent for Oil/Gas Fired Appliances, Installation and Maintenance Manual", Energy Vent Ltd., 241 Arvin Ave., Stoney Creek Ontario Canada L8E 2L9, web search 10/15/2010 original source: www.selkirkcorp.com/WorkArea/downloadasset.aspx?id=2380 www.selkirkcorp.com/WorkArea/downloadasset.aspx?id=1802
  • Chimney Inspection Checklist, Carson Dunlop, Associates, Toronto, Ontario
  • Chimney & Stack Inspection Guidelines, American Society of Civil Engineers, [Book] 2003 ISBN: 9780784475423

    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: Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances, (2024) at the NFPA Bookstore, (Older NFPA editions and standards are found at the same bookstore)
  • Principles of Home Inspection: Chimneys & Wood Heating, in (Principles of Home Inspection), Carson Dunlop, Associates, Toronto, Ontario
  • 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
  • American Gas Association - New Vent Sizing Tables
  • Chimney Safety Institute of America - Chimney Fires: Causes, Effects, Evaluation
  • National Chimney Sweep Guild [Website] 1255 SW Prairie Trail Pkwy Ankeny, Iowa 50023 USA, Tel: +1 (317) 837-1500 Email: office@ncsg.org NCSG certifies chimney sweep (cleaning) professionals.
  • In addition to citations & references found in this article, see the research citations given at the end of the related articles found at our suggested

    CONTINUE READING or RECOMMENDED ARTICLES.

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