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CHIMNEY INSPECTION DIAGNOSIS REPAIR
BACKDRAFTING HEATING EQUIPMENT
CARBON MONOXIDE - CO
CHIMNEY CAP & CROWN
CHIMNEY CLEANING PROCEDURES
CHIMNEY COMPONENT DEFINITIONS
CHIMNEY CRACK DETECTION & DIAGNOSIS
CHIMNEY DRAFT & PERFORMANCE
CHIMNEY FIRE ACTION / PREVENTION
CHIMNEY HEIGHT & CLEARANCE CODE
CHIMNEY INSPECTION, FLUE INTERIOR
CHIMNEY LEANING, SEPARATION, MOVEMENT
CHIMNEY REPAIR METHODS
CHIMNEY STAINS & LEAKS
CHIMNEY TYPES & MATERIALS
DIRECT VENTS / SIDE WALL VENTS
DRAFT HOOD, GAS HEATER
DRAFT REGULATOR, DAMPER, BOOSTER
FIRE CLEARANCES INDOORS
FIREPLACES & HEARTHS
FLUE VENT CONNECTORS
MASONRY CHIMNEY GUIDE
METAL CHIMNEYS & FLUES
SAFETY RECALLS CHIMNEYS VENTS HEATERS
SOOT AT CHIMNEY TOP
STAIN DIAGNOSIS on BUILDING EXTERIORS
WOOD, COAL STOVES & FIREPLACES
Chimney, Fireplace & Woodstove information home page:
This article series on chimneys, flues, and vents and on fireplaces & woodstoves explains how to inspect & detect defects and hazards in these heating systems & components. We also provide chimney & fireplace repair advice along with chimney repair alternatives such as relining vs. replacement. Chimney and flue safety hazards such as carbon monoxide gas leaks, fire hazards, and chimney inspection and testing are addressed.
Guide to chimney inspections: this series of detailed chimney articles provides 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.
Green links show where you are. © Copyright 2014 InspectApedia.com, All Rights Reserved.
In our page top photo, a single wythe brick flue had lost some of its bricks. The owner "fixed" this condition by propping a board against a piece of aluminum flashing to cover the hole in the chimney.
This chimney inspection article series describes and illustrates chimney inspection procedures and critical chimney defects which can be observed from outdoors at ground level, from the rooftop, from inside the building, and finally, by inspecting the interior of the chimney flue itself.
Where do you think the missing bricks were?They were not on the attic floor. I had been called to the building to investigate a basement water entry problem.
This is what we found: a single wythe brick chimney in a tall two story house with full basement. The water on basement walls was condensate from flue gas spillage from the gas fired heating boiler whose flue was totally blocked by the fallen bricks and debris.
This was a serious carbon monoxide hazard and a dangerous chimney. The details of this case are presented at UNLINED FLUE INSPECTIONS. Our photo at left shows a client joining us in beginning to investigate the separation of a chimney from the house gable end wall.
At page left are links to detailed articles about all types of chimneys and flues: their construction, installation, inspection, diagnosis, and repair. Below we describe some key chimney troubleshooting articles.
We begin with some basic definitions of chimneys and chimney types, followed by an outdoor chimney inspection beginning at ground level. the detection of chimney movement, its causes, its symptoms.
Our metal chimney photo (left) illustrates a single-wall 1960's vintage fireplace chimney that was set into a solid masonry fireplace.
But this installation is no longer safe to use - it's too close to the second floor addition wall, and too short.
A chimney must be moisture and gas tight and convey the products of combustion to the outside atmosphere.
It sounds like a simple job, but it may not be simple, nor inexpensive.
Because chimneys are exposed to weather, high and low temperatures, water and moisture, squirrels, nest-building hornets and birds, corrosive gases, occasional incompetent builders or installers, combustible products, potentially fatal flue gases, and even sparks that could cause a fire, and because proper venting of flue gases is necessary for safe and efficient heating system operation, a periodic and careful chimney inspection is important.
A combination of these three things:
This chimney information home page catalogs and gives details of chimney problems that can be observed from outside and from inside of a building. A naturally drafted chimney for natural gas or oil fuel appliances lasted many years because of the hot gases venting up through the clay flue.
Changes in the way chimneys are used, including changes from coal, wood, or oil heat to natural gas adds still more chimney problems, some of which are dangerous.Outside, by attending to even minor clues we might detect improper or unsafe heating system operation, collapse hazards, building leaks and water damage, and other concerns.
Of these, most critical and life threatening problem for which a home inspector or homeowner should be alert is the risk of leaks of combustion products into the dwelling - gases which could contain the sparks of a fire or the threat of fatal carbon monoxide poisoning.
The photo at above left shows a cracked chimney top seal or "crown" and also that there is no chimney cap installed. Notice my green pen [DF] sticking right into the chimney masonry at the top? Water and frost damage are risks for this flue. What else can we see on this chimney top?
The flue looks pretty clean - perhaps
this is a gas-fired appliance. The top clay liner looks good - at least the part
we can see in the photo, but don't assume anything about the rest of the flue
before it's inspected. See the individual chimney inspection procedures and defects described
Inside the building we may spot abandoned chimneys, unsafe chimneys, fire hazards and flue gas hazards. During the chimney inspection we may see little clues which point to potentially serious concerns, like broken clay flue tile liner parts in the bottom of a chimney cleanout opening.
See CHIMNEY INSPECTION INDOORS for details.
When do Chimney Codes Apply to Existing Chimneys?
NFPA 54, the National Fuel Gas Code, recommends that when a new appliance is retrofitted into an existing installation, or an existing appliance is removed from a common vent, the entire venting system, which may include a masonry chimney, should conform to current codes.
Many houses inspected have had higher efficiency appliances installed, some direct vented, and we observe corroded vent connector pipes, corroded chimney cleanout doors and disintegrated masonry at the cleanout.
Definition of Chimney: A chimney is a structure manufactured or constructed to form and enclose one or more vertical passages (flues) through which products of combustion pass to the outside atmosphere.
A masonry chimney needs to have a sound foundation to prevent settling and movement, and must be soundly constructed so as not to leak combustion gases as well as to prevent setting the building on fire. See CHIMNEY TYPES & MATERIALS. In Carson Dunlop Associates' sketch just below, the lower end of a masonry chimney structure is visible at the left of the photo.
Definition of Flue or Chimney Flue: A pipe or shaft for the passage of smoke, hot air and gas in a chimney. A single masonry chimney may contain more than one flue.
[Click to enlarge any image]
There are important safety regulations about the construction, separation, and use of chimney flues within a chimney. In general chimney flues are not shared among devices on different floors, and sharing of flues among devices on a single floor is limited to certain heating equipment combinations.
See CHIMNEY INSPECTION, FLUE INTERIOR for details. Also see our Q&A below that defines chimney flue again and explains flutes that appear on pipe organs - nothing to do with heating appliance chimneys.
Carson Dunlop Associates' sketch at left shows a horizontal flue vent connector inserted into the chimney flue. The flue or chimney interior is shown in cross-section. In this example debris has clogged and blocked the chimney - producing a dangerous condition.
Definition of Vent Connector or Flue Vent Connector: A vent is a manufactured product intended only to serve a specific type of appliance under narrowly defined conditions. For example, the thin-walled metal pipe, typically 6" in diameter or larger and used to connect an oil-fired heating boiler or a gas-fired furnace to a metal or masonry chimney is properly called the flue vent connector. Lots of people call this component the "flue pipe" or "stack pipe".
There are important safety regulations about the components, installation, fire clearances, and fire ratings of flue vent connectors and their component parts. See FLUE VENT CONNECTORS, HEATING EQUIPMENT for details about the inspection, installation, hazards, and repairs of flue vent connectors.
All chimneys whose construction is entirely internal to the building structure up to the roof line are considered inside chimneys.
Chimneys with three walls exposed to the outdoors are considered outside chimneys. Vents may experience continued condensation. A "Type B" vent or a listed chimney lining system passing through an unused masonry chimney flue is not considered to be exposed to the outdoors, but a type B-vent or other metal chimney passing through an exterior wall chimney chase would also be considered an outside chimney.
Outside chimneys, because they are exposed to colder temperatures than a chimney that passes through the building interior, may have different draft and performance properties and in some circumstances may not provide adequate draft. We discuss examples of this concern at CREOSOTE FIRE HAZARDS.
Three Sided Chimneys
A three-sided or "three walled chimney" is one which does not provide full masonry thickness or fire protection around all sides of the chimney flue. Three sided chimneys can be a very serious fire risk because the chimney has been built close to or even directly against combustible building materials without the necessary fire clearance and masonry fire protection needed. See Three-Sided Chimneys: Outdoors for details.
The chimney wall has two primary functions: structural and draft inducing or thermal performance. Masonry chimney walls are generally built of brick, stone or concrete masonry units. Codes dictate the thickness and mortar requirements. All concrete products must be waterproofed and all mortar joints solid through the thickness. Masonry chimneys may not be supported on structural elements of the building.
Masonry chimneys must be fully self supporting. See BRACKET CHIMNEYS below for an example of chimneys that are not self-supporting.Our photo (left) 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 are other defects as well. Notice the glass chemical fire extinguisher hanging from the ceiling? Will that be effective against a fire at the chimney? (And are its contents toxic?)
Abandoned chimneys that have been partially removed may also be structures that are no longer self supporting. Surprising to some people is the discover that the lower portion of an internal masonry chimney has been removed in a building, leaving the inadequately-supported weight of remaining chimney sections in an attic or on upper building floors.
This article will discuss when and why chimney flues are re-lined and lists a few of the chimney repair or relining alternatives. Selection of the chimney liner system depends on the configuration of the flue.Straight flues are not difficult whereas offset flues will require a flexible liner system or the removing of brick work at the offsets so that angle fittings can be installed.
Both flexible and single wall rigid metal liners can be insulated to further avoid condensation. This is very important in cold climates and for high chimneys. See Re-Lining Choices for Masonry Chimneys for details.
Spalled brickwork can be replaced brick by brick or the chimney can be rebuilt after tearing it down to a sound level. This allows for new flue tiles to be installed if needed. Cracks need to be evaluated to identify the cause - a crack may indicate serious chimney movement, structural damage, risk of collapse, flue gas and fire hazards, or improper construction leading to thermal cracking. See CHIMNEY CRACK DETECTION & DIAGNOSIS.
Metal components can be replaced and single-wall flue connectors, if corroded on the bottom of horizontal sections, can be replaced with Type B or L flues which will maintain the flue gas temperature and minimize condensation.
See REPLACEMENT PARTS for METAL CHIMNEYS for details.
CHIMNEY INSPECTION DIAGNOSIS REPAIR provides a detailed guide to visual inspection of all types of chimneys and flues.
Life Safety Hazards at Chimneys such as visual evidence of unsafe chimneys, fire hazards, flue gas and carbon monoxide hazards, missing or damaged safety devices (relief valves, emergency shutoffs),
and visual evidence of dangerous overheating or leaks. Life safety hazards also include collapsing chimneys.
Watch out: At UNLINED FLUE INSPECTIONS we describe a scary story that happened when we identified an unsafe chimney and advised our client to have a chimney expert inspect and repair the condition. She called a chimney company listed in her local telephone book. But the "expert" was so poorly informed about chimney safety that his "repairs" came close to killing the occupants of the house. See Chimney Cleaning Advice, Procedures.
Watch out for consumer fraud and scam operations that promise low-priced specials on chimney inspection, cleaning, re-lining, or repairs. Readers have informed us of a variety of common chimney rip offs involving professional criminals who combine information about new home buyers and local business names with a telephone promise of various chimney services such as chimney cleaning for $39.95.
Homeowners attracted to this chimney deal may encounter scammers who arrive with a ladder, take a superficial look at a chimney, and claim that the chimney is unsafe, needs re-lining, or other treatment.
Details about chimney repair frauds and chimney cleaning scams are at CHIMNEY CLEANING FRAUD
Index to Chimney Inspection & Troubleshooting Articles
Here is an alphabetical list of chimney codes, chimney construction, chimney cleaning, chimney diagnosis & chimney repair articles found at InspectApedia.com. Also try the SEARCH box found at the upper right of each of our pages or at the end of each article.
Continue reading at CHIMNEY TYPES & MATERIALS or select a topic from the index of chimney articles listed above.
Suggested citation for this web page
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
Question: how do we measure the draft at a chimney?
How are chimney draft inspected. - Louie
Reply: we use a draft gauge, instruments ranging from simple and inexpensive to more sophisticated; measuring draft vs "inspecting" chimney draft - how to measure Chimney Draft
We use a draft gauge - a sensitive instrument that compares relative pressures at two locations - such as in the room and in the chimney.We can actually measure the draft in a chimney using a draft gauge - heating service technicians have this equipment. Draft can be measured at just about any chimney, but is discussed in detail where we explain the draft regulators used on heating equipment - see DRAFT MEASUREMENT, CHIMNEYS & FLUES.
"Inspecting Chimney Draft"
Because chimney draft is a number, we can't actually "see" draft. But an experienced home inspector, heating service technician, or chimney installer may indeed spot serious, even dangerous trouble, including chimney draft problems just "by eye" when inspecting heating equipment, fireplaces, building roofs, and chimneys themselves.
That's because lots of serious chimney defects that involve chimney draft can be caused by visible building conditions - such as a heating appliance installed in a tiny closet with no combustion air supply and an airtight door to that room, or a visibly cracked or damaged chimney, or a missing chimney cleanout door, leaving the chimney bottom open.
Other chimney draft problems might be "inspected" or I should say inferred by visual clues that telltale heating equipment operating trouble often traced to inadequate or even excessive draft - such as chronically sooty oil burner operation or an oil burner that keeps burning off the front of the appliance.
Question: What and where are the soffit, fascia board and are they parts of a chimney? What is a "corible"
where is the "soffit" and "fascia board" on a chimney? I was told they need caulked. And what is a "corible". I was told it needs sealed. Thanks. - Rick
Reply: soffit and fascia are roof edge trim components. Corbelling is stair-stepping in brick work, often used to angle a chimney over to a desired location.
Rick, you got me on that question. Soffits on building exteriors are the enclosed lower portion of the roof overhang or roof edge, also called "eaves".The fascia board (green arrow in our sketch at left) is a vertical board running parallel to the roof edge on the outer edge of the soffit - usually it's covered by the roof edge gutters.
A soffit is a general term for a boxed-in overhang and might appear indoors in a kitchen over cabinets. In our roof sketch (left) the soffit is pointed to by our red arrow. The sketch at left is provided courtesy Steven Bliss & J Wiley & Sons 
Corbelling: Corible - sounds like something "horrible" and isn't a word I've heard nor been able to find in building dictionaries except perhaps used as a term for button-like decorations around a section of building, roof, or chimney trim.
I suspect your contractor meant "corbelling" (photo at left, some spell corbelling) which refers to a stair-stepped or sometimes simply "slanted" chimney construction that allows the mason to angle a chimney off to one side in order to send it where the building designer or architect wanted. For example a corbelled chimney may stair step to one side in an attic in order to exit the roof right at the ridge rather than extending straight up from lower floors to a lower roof penetration location.
See our "House Parts" dictionary at HOUSE PARTS, DEFINITIONS to see a building sketch that defines different parts of the house, or see ROOF VENTILATION SPECIFICATIONS for photos & sketches of what roof soffits and fascias look like.
Question: how to deal with birds invading the chimney
I have birds that built nests in the inner wall of my 3 wall liner. The inspector said the nests have pushed down the pipe and that the flue will need to be removed and cleaned and then reinstalled. He estimated it could be around $1,800! I have access to the back of my fireplace and asked if the flue can be disconnected from the fireplace and then raised enough to push the nesting down while someone pushes from the top. Has anyone ran into this or have a suggestion on how I should fix this so I can use this fireplace? Thanks Terry
Terry I too have been absolutely stunned by recent quotes from chimney installation and repair companies. I don't have a full nor accurate picture of your chimney design and installation, but it's reasonable for you to
Question: An orange powdery material is leaching through the flue of an old unused chimney - what is it?
I've got an orange powdery material leaching through the flue of a chimney that was seal off about 1-1/2 years ago. Any ideas as to what the substance might be? - Dan
Reply: check out efflorescence and look for a chimney leak
Question: noises coming from inside the chimney when it's windy - like a tennis ball?
i have a strange noise coming from inside my house chimney when the wind gets strong something like a tennis ball rattling around what could it be - Steve
Steve, I don't know, but some guesses include
Question: Is it safe to remove asbestos chimney parts?
is it safe to remove a asbestos chimney pot, if it can be removed without touching it. ie taking the mortar from around it carefully lifting it out straight into a asbestos bag - Aharri 12/16/11
I'm not sure I've got an exactly clear picture of what you're facing. A "chimney pot" in my parlance is a ceramic chimney top fixture that extends chimney height, can also form a cap, and is usually molded for architectural or aesthetic reasons. I've not found one of those made of asbestos. Perhaps you could send us some sharp photos (use the CONTACT link on our pages). In general, if you are referring to nonfriable material such as a transite flue section in good condition, that can be simply lifted free and bagged, that sounds reasonable to me. The ancillary fiber release outdoors one would expect to be below detection.
Question: water leaks through our chimney during rain
There has been a lot of rain recently and our chimney was blocked off 3yrs ago and water has started to drip down onto where I have my electricals. When the rain stopped, it stopped coming in. Could it be a damaged flue? The plaster board was soaking as if it had been happening for a while but we only noticed yesterday. - Ruth 4/30/12
Question: our chimney liner is intact but not straight - the cleaner says I need to replace the liner due to backpressure.
I had my chimney inspected,the liner is in tact but it is not in straight alignment. The chimney cleaner said I need to replace the liner because it is creating back pressure. Am I being scammed? I called them because them because I had a blow back, which I believe came from a dirty nozzle - Joe B 4/6/12
Joe I can't second guess your chimney cleaner with so little information - we and you need some clear specifics, maybe a chim-scan video of the chimney interior. A chimney does not have to be dead straight to function properly. But if you had an oil burner puffback then it's possible that the chimney was damaged. It's not something to take a chance-on. Look for a chimney sweep who is a member of a professional certifying association, ask for a complete safety inspection, and a written report of the results. Also see CHIMNEY FLUE INSPECTION CAMERA for a discussion of chimney inspection camera systems.
Question: Definition of chimney flue. What is a chimney flue? What is a chimney flute?
Is it incorrect to say "close the flute" or is it "close the flue"? - Vanna 7/27/12
Reply: chimney flue - chimney flues vent heating appliances; flutes and even chimney "flutes" appear on pipe organs for making music
We close the chimney flue by closing the flue damper. A chimney flue (not flute) is the passage inside of a masonry chimney or inside of a metal chimney that allows smoke, heat, and gases of combustion to pass up the chimney to be vented safely above the building. At a fireplace the chimney flue begins immediately above the smoke shelf above the fireplace itself.
At a heating appliance such as an oil or gas fired heating boiler or water heater, the active chimney flue begins at the point of insertion of the flue vent connector into the chimney.
The flue vent connector is a metal pipe that connects the heating appliance to the chimney and chimney flue. In our photo at left our client is pointing to the (leaky) point at which a horizontal flue vent connector is inserted into the chimney flue. In our photo at left those two rectangular openings are the very top of two independent chimney flues.
See CHIMNEY INSPECTION, FLUE INTERIOR for details.The term "chimney flute" does indeed occur and is used [correctly] to refer to certain German translations for pipe organ parts, and for pipe organ parts. In documents describing the pipe organ - by which we refer to the musical instrument with a keyboard and air-driven sounding pipes that play various notes and chords - the term "flue pipe", "flute pipe", labial pipe, and also chimney flute all appear. In pipe organs, the "flutes" or "flute pipes" are the widest, elemental or low note producing pipes on the instrument. 
Watch out: However, perhaps from German or Old English, and also occasionally among people who are careless with language, we find articles written about heating appliance chimneys and flues that refer to the chimney "flute". Baloney. If you come across a purportedly technical article about heating appliance chimneys that does not know the proper name for building parts, I'd be careful about trusting the advice offered there.
Question: smoke problems from a neighbor's chimney
I am wondering if there is some law about smoke from neighbors chimney. I have COPD and cant hardly breathe in my own home. The smoke rolls in sometimes and it makes me very sick then I have to go pay a doctor. Thats not fair to me. It may be costing them less but it is costing me almost $200. a month more now. Please help me breathe. What can I do? - J.C. 12/28/2012
A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem with a chimney or venting problem. That said, here are some things to consider:
First: f your neighbor's chimney is smoking it may indicate conditions that are unsafe for those people as well, such as an unsafe or improperly-operating heating system. Therefore it makes sense to be sure to tell your neighbors about the smoke and that there are possible safety concerns (as well as unnecessary heating costs) - the system and chimney should be inspected and cleaned/adjusted if appropriate.
Second, if a chimney is improperly constructed, such as wrong height or location, it may not provide proper draft - again potential safety or heating equipment operating problems, and as well it may be in violation of local building codes.
There are building code regulations and standards for chimney and heating appliance venting and chimney construction, but I'm not aware of specific rules about smoke intrusion. Rather a chimney, properly installed an designed, should not discharge smoke where it may enter its own building nor another one nearby. By no means do I encourage an argument with a neighbor, but if your neighbor is simply uncooperative, you may be forced to ask your local building inspector to take a look and to advise both you and the property owners if there are unsafe or improper conditions.
Question: Does California’s Code allow that fire place vent be together with other exhaust ducts? Installation specification details for chimneys / vents when installing a gas fireplace
I am mechanical engineer with 15 years of experience in Serbian and Russian market. I have been working for American market for a couple of month and I would like to ask you to help me with my problem. I apologize in advance about my English but I hope you will be able to understand essence of my question.
[Click the image at left to see the complete architectural drawing of fireplace vent and kitchen bathroom vent and vent shaft drawing]
In some non-residential building in Oakland CA, I have units with fire place at living room. Architect wants that fire place vent be in shaft up to roof. In that shaft are also toilet exhaust duct and kitchen hood exhaust duct (sub-ducts within metal duct which will be conjoined at the roof with common fan). I tried to find if that option is permit and what will be demands for that but I couldn’t.
I am sending you also drawings for easier understanding.
I am looking forward to your answer. Thank you in advance.
Best regards, - S.V. 8/14/2013
Thank you for the questions S.V.
You won't find any code that permits using a fireplace chimney vent also for venting other exhaust ducts thorugh its interior. Such an effort would be very dangerous, risking a building fire as well as causing improper operation of all of the appliances or vents being so-joined. For example, we do not run wires, gas lines, and certainly not a chimney within the interior of a heating or cooling air duct or similar building feature.
Depending on the chimney materials and type and the size of an existing passage through a building, it may be permitted to route a UL listed metal chimney through a larger chaseway inside of which other vertical vents or air ducts are also routed provided proper fire clearances are respected and that proper construction prevents any possible leaks or interference. Using such a chaseway for multiple purposes must consider the number of bends, turns, slope, overall dimensions, height, and fire clearances, and certainly the plans for such a structure need to be submitted, approved, and inspected by local building officials.
You made me speechless with your answer! Thank you very much. The architect didn’t want to put other exhaust ducts into the chimney; he said "Please vent the fireplaces in Units C1 & C2 to the roof through the adjacent bathroom vent shaft as drawn.". It sounded like bad solution to me, that is the reason why I asked you for help. If that isn't to much I will send you pdf file as well. The fire place is Heat&Glo type SL-550 TR-E, natural gas. Yes, I don't have any expirience in fire place ventilations - that is a reason I want to learn it! ( I have been working for american market since January.) Thank you so much once again, I will read all that for sure
I appreciate the discussion - working together makes us smarter; The first image I enclose, cut from your pdf, looks to me like a gas fireplace direct side vented out through a wall and over a stairwell which, if the vent is actually in or close to the walking path of people, something that to mee seems improper.
That same unit ... has a vent for kitchen and bath nowhere near the fireplace. Seems to me the architect has got himself into a tight spot here and just "tossed the probelm over the wall to you saying "fix it" - asking you to do his job. I'd be careful about working with whomever that is. I'm not sure what s/he had in mind when these plans were drawn.
Indeed there are direct-vent gas fireplaces that can avoid the need for a chimney; some of these can vent horizontally OR vertically but have to terminate at an acceptable location which I doubt to be along a stairway.
In the REFERENCES section of this article you'll find some key codes & texts you'll want to review for chimney and fireplace installation and safety.
You made me speechless with your answer! Thank you very much. The architect didn’t want to put other exhaust ducts into the chimney; he said "Please vent the fireplaces in Units C1 & C2 to the roof through the adjacent bathroom vent shaft as drawn.". It sounded like bad solution to me, that is the reason why I asked you for help. If that isn't to much I will send you pdf file as well. The fire place is Heat&Glo type SL-550 TR-E, natural gas. Yes, I don't have any expirience in fire place ventilations - that is a reason I want to learn it! ( I have been working for american market since January.) Thank you so much once again, I will read all that for sure.
The first image I enclose, cut from your pdf, looks to me like a gas fireplace direct side vented out through a wall and over a stairwell which, if the vent is actually in or close to the walking path of people, would be flat crazy. That same unit #205 has a vent for kitchen and bath nowhere near the fireplace. Seems to me the architect has got himself into a tight spot here and just "tossed the probelm over the wall to you saying "fix it" - asking you to do his job. I'd be careful about working with whomever that is. I'm not sure he's doing what he was paid for. Indeed there are direct-vent gas fireplaces that can avoid the need for a chimney; some of these can vent horizontally OR vertically but have to terminate at an acceptable location which I doubt to be along a stairway.
Also it occurs to me that if you contact the fireplace manufacturer they will probably be glad to help with a more detailed spec on how their unit can be safely vented. Also see the citations I offer at http://inspectapedia.com/chimneys/Chimney_Inspection_Repair.htm#reviewers (click to show) for some key chimney and fireplace codes and specs sources.
Reader remark: Well yes...It seems that everyone chase for form only, not for essence. That vent over a stairwell is ok, I check in Installer Guide.
Reply: I think you can vent over an exterior stairway PROVIDED there is adequate overhead clearance from the walking space. Otherwise you will or may run into stair code violations such as intrusions into the walking space or stairway headroom. We publish stair clearances too if you need to check that.
Reader comment: In installer guide is written - 7ft clearance from public property and the architect provide that. Anyway, when I told to my menager my doubts she didn't have answers on them and the result is that project is postpone till next week. I wrote to the manufacturer and I won a coupon for fire place!(?!). It will be much easier next year when I move to America! Right knoow I just want to find out is it possible to put vent pipe into the same shaft or into the drop ceiling with others exhaust ducts.
Reply: "the vent pipe" is just too vauge. There are multi-wall insulated chimney materials typically described as "zero clearance" that can be put typically 1" from combustibles; B-vents have different clearance requirements. You are also not adequately addressing issues of chimney venting design: angles, bends, lengths of run, horizontal distances, and as a result possible code violations as well as fireplace draft hazards. I would BE VERY CAREFUL to review the design against the manufacturer's specifications and also national model codes as well as local codes because especially with a gas fireplace it is very easy to produce fatal carbon monoxide gas (and kill the occupants) if a gas fired appliance does not vent properly.
Reader comment: I agree with you completely.That is the reason why I insist on codes or regulations. Firstly, the architect wanted to go with that pipe thru whole bedroom ( from one side to another) and I avoid that. Can you recommend me which codes will that be? As I said, I typed every possible solutions of the words, but I couldn't find anything.
Reply: In the citations to my chimney articles you can find good details in the US national fuel gas code, and also there are NFPA specs on chimneys. But to really cover yourself a checkmwith the technical representative for the gas fireplace company is important too - they want their product to be safe.
Reader comment: I tried to get in contact with Heat & Glo but only I did is to get a coupon of 100$ for a fire place!
Reply: contact information & manuals, architect's guides & CAD drawings for Heat & Glow Gas Fireplaces
at http://www.heatnglo.com/ I found this contact information
Heat & Glo A Brand of Hearth & Home Technologies Inc. Corporate Office 7571 215th Street West Lakeville, MN 55044 Phone: 1 (888) 427-3973 Email: email@example.com
and at the same website the company offers some installation manuals for professionals
as an example I looked at the PDF installation manual for their LUX fireplace series - on p. 26 are specifications for fireplace venting for this natural gas fired model. There you will see the rules for allowable chimney vent runs for horizontal, angled, and vertical lengths and probably fire clearances as well. There are some important restrictions; here are two examples (th examples are incomplete and thus NOT a complete and safe installation specification)
LUX36 requires a minimum of 36 inches of vertical venting before attaching any elbow to the appliance for the venting configuration (in an example fiture 4)
LUX42 requires a minimum of 48 inches of vertical venting beforeattaching any elbow to the appliance.
Try contacting the Heat & Glo Fireplace company by email at the address I gave above. Also - once you've identified the specific gas fireplace model to be installed, you will want to look at ALL of the installation manuals and guides. I notice there are installation instructions and also an "Architect's Guide" for using these gas fireplaces. There are also some CAD drawings. Among these key documents you will find rather detailed specifications of the constraints that must be respected in framing, installing, and venting the gas fireplace.
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