Thread: Type B Vents

Type B vents are double walled to help the flue gases move forward in the unconditioned spaces. Now if I have a single walled vents through out the chain, then do I have to buy a whole new type B apparatus or I can just wrap a sheet metal jackets on the current venting and have the double walled feature of Type B vents. Would save me much cost and also a lot of time.

The vent system goes from 80% Eff. 60K BTU natural gas furnace in the basement and goes vertical after 5 feet passing through attic and then out the roof.

Also, if I have to do the Type B stuff then can it be replaced by PVC deals at 5". Would save immense amount of time although might cost much more.

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Originally Posted by NMatts

Type B vents are double walled to help the flue gases move forward in the unconditioned spaces. Now if I have a single walled vents through out the chain, then do I have to buy a whole new type B apparatus or I can just wrap a sheet metal jackets on the current venting and have the double walled feature of Type B vents. Would save me much cost and also a lot of time.

The vent system goes from 80% Eff. 60K BTU natural gas furnace in the basement and goes vertical after 5 feet passing through attic and then out the roof.

Also, if I have to do the Type B stuff then can it be replaced by PVC deals at 5". Would save immense amount of time although might cost much more.

Cant have SW through an attic. Wrapping SW isnt going to help much. SW has a 6" clearance to combustible.

What is SW, can't figure this out. Would using 5" diameter PVC help.

Originally Posted by NMatts

What is SW, can't figure this out. Would using 5" diameter PVC help.

SW= Single wall. 80% AFUE unit most likely will not allow the use of PVC.

You say can't have SW through an attic. Fine. I was presuming that it is SW through out. I will have to get to various levels to make sure of what type venting it is. I had the home inspected before buying 7 years ago. Would the inspector have checked this out that there is a Type B in the attic atleast. Also, the previous furnace was some 30 year old Anthes 60K BTU brand. Were the real old furnaces ok with the SW or they required Type B also.

Also, would covering SW by pink insulation throughout help any and more so because...........

The insulating materials in PINK® fiberglass insulation are noncombustible. Its natural fire resistance is unaffected by moisture, evaporation, or time, which makes Owens Corning insulation a very reliable product.

Originally Posted by NMatts

You say can't have SW through an attic. Fine. I was presuming that it is SW through out. I will have to get to various levels to make sure of what type venting it is. I had the home inspected before buying 7 years ago. Would the inspector have checked this out that there is a Type B in the attic atleast. Also, the previous furnace was some 30 year old Anthes 60K BTU brand. Were the real old furnaces ok with the SW or they required Type B also.

Its not the furnace that is of issue its the vent type and the vent clearances that is of issue. Even if "IF" SW was allowed to be run through an attic, now its not. At some point in time, a fire or fires resulted, or even death or multiple deaths. Its sort of how code and law come about. Its all about safety. Personally, as an HI, my #1 concern is my clients health and well being.


10.1.6.3
Single-wall metal pipe shall be used only for runs

directly from the space in which the appliance is located,
through the roof or exterior wall to the outer air.

10.1.6.4
Single-wall metal pipe shall not originate in any unoccupied
attic or concealed space and shall not pass through
any attic, inside wall, concealed space, floor, or ceiling.

You say the furnace is in the BASEMENT and that there is an ATTIC: This implies at least one "floor" or story, if not two, of occupied space between same. You say the "furnace" is 80%, you don't say if natural draft. Not "sold" on the "idea" that B-vent is necessarily the correct venting system in the first place, in NO case can you do ANY of the "deals" "stuff" or DIY "stuff" you suggest, and do so safely. If/when someone is hurt, dies, you would be responsible. From what you have stated, YOU should NOT be doing ANYTHING EXCEPT HIRING A Licensed PROFESSIONAL to evaluate and perform the work, and doing so IMMEDIATELY. B-VENTing SYSTEMs must be enclosed (with sufficient SPACE clearance within), behind stopped walls on all occupied floors. It must be sufficiently supported, fire stopped and blocked where it passes through floor/ceiling ssemblies, at least every 10' vertical, at any change in direction, and within the CHASE between the equipment in the bsement and origination of the B-Vent system (well below the ceiling assembly in the bsement) and through the occupied space. Your Attic is apparently occupied (used for storage, or whatever) so a chase there is likewise needed, you may insulate the CHASE wall, beyond the inner gyp wall liner, NOT the B-VENT. YOU MAY NOT ENCASE the vent with PVC or sheet metal or insulation. All trap and hold/reflect HEAT. A 1" minimum AIR SPACE clearance is required for b-vent trade size 12" or less.

Originally Posted by NMatts

Type B vents are double walled to help the flue gases move forward in the unconditioned spaces. Now if I have a single walled vents through out the chain, then do I have to buy a whole new type B apparatus

YES it has to be purchased as a listed system and componants thereof, it MAY NOT BE "field fabricated". I do NOT suggest YOU buy anything. Hire a Licensed trained professional to determine the correct trade size, draft (min & max), length, effective length, and to fully specify, configure, and install.

or I can just wrap a sheet metal jackets on the current venting and have the double walled feature of Type B vents.

YOU MAY NOT DO THIS, Absolutely NOT. What YOU CAN and CAN NOT do is irrelevant, and no, it would NOT have that effect.

Would save me much cost and also a lot of time.

Irrelevant.

The vent system goes from 80% Eff. 60K BTU natural gas furnace in the basement and goes vertical after 5 feet passing through attic and then out the roof.

A minimum rise is required from the appliance flue prior to ANY lateral orientation. Lateral MUST still have rise. It would seem obvious that between the ceilng/floor assembly above the basement, and the floor/ceiling assembly of the "attic" there must be a story or two of OCCUPIED SPACE. So you fail to provide even the minimum details. You make no mention of a water heater or boiler, which I suspect you also may have, and likely sharing the system. Of course, perhaps you don't have a "furnace" at all but a boiler providing both hydronic heat and potable hot water. Frankly suspicious we are NOT discussing a true single family home, perhaps a manufactured one upon a basement, or perhaps other than single-family free-standing configuration?? 30 y.o. "home" Iowa. 60k, Hmmm.

Also, if I have to do the Type B stuff

what is "B Stuff"?

then can it be replaced by PVC deals at 5".

No use of PVC, certainly not for any Cat. I, II, or III, ANYWHERE.

Would save immense amount of time although might cost much more.[/quote]

What is SW, can't figure this out.

single wall vent or chimney CONNECTOR (not vent).

Would using 5" diameter PVC help.

NO, you may NOT use PVC, for 80% natural draft (Category I), period!

You say can't have SW through an attic. Fine. I was presuming that it is SW through out.

You presume too much. You REQUIRE a trained professional and a vent/chimney INSPECTION regarding condition, sufficiency, etc. in addition to draft proving. It seems obvious you do NOT know what you have, or its condition, at all.

I will have to get to various levels to make sure of what type venting it is.

It doesn't seem you are qualified to determine this, I STRONGLY recommend a PROFESSIONAL Level II.

I had the home inspected before buying 7 years ago.

Really? are you sure? A VA, HUD, FHA, or USDA Rural insured program "inspection" is not a "home inspection" it is a asset qualification verification (semi appraisal) not a "home inspection".

Would the inspector have checked this out that there is a Type B in the attic atleast.

Perhaps yes, perhaps no. Was it exposed and able to be accessed, seen without obstruction, movement of anything, was the attic accessible? DID YOU READ your Inspection Report? You should STILL HAVE IT, read it, see what it says.

Also, the previous furnace was some 30 year old Anthes 60K BTU brand.

So you or someone else has had a different ("new"?) "furnace" installed subsequent to your having had some sort of "inspection"(?) prior to your purchase of this home?Who installed this "new furnace"? When? Who performed a minimum Level II inspection of the chimney system or vent system and determined its functionality and appropriateness for service to this "newer" "furnace" installation? Unlicensed, unpermitted, uninspected?? The Installer of the "new furnace" had responsibilities regarding the inspection of, determination of the "venting system", "chimney", connectors, of same, etc.!!!

Were the real old furnaces ok with the SW or they required Type B also.

IT DEPENDS. I'm not certain your questions or descriptions can be trusted. Manufactured Chimney vs. Vent, site chimney, stove pipe, vent & chimney connectors, chases, flue liners, etc.

Also, would covering SW by pink insulation throughout help

NO, NO, NO!!! SW requires absolute MINIMUM of 6" of FREE AIR SPACE, MAY NOT PASS directly through walls or floors and may not vent through other stories of occupied space, or be used in unconditioned, unoccipied space. NOTHING may be in this air space, it is NOT just a combustibles clearance it requires AIR space. Covering single wall vent connector with insulation is a most stupendous, dangeours, ignorant "idea"!

any and more so because...........

The insulating materials in PINK® fiberglass insulation are noncombustible. Its natural fire resistance is unaffected by moisture, evaporation, or time, which makes Owens Corning insulation a very reliable product.

Who cares? It belongs nowhere in, on, or upon a venting or chimney system or connectors thereto, and most certainly not within the REQUIRED AIR SPACE CLEARANCE abutting all aspects of same.

Get a licensed PROFESSIONAL.

Ditto H. G.

There are many thing in a home that DIYer can do, but based on your questions, you absolutely need a professional. We constantly see where smart guys thought they had figured out a common sense "fix", but they end up just figuratively putting lipstick on an alligator, and still have a beast of a problem.
Fork out the dough, and pay a pro to fix your vent.

Just checked today and went to the attic also. It is a type B vent all the way. It starts from the end of 3-4 feet of horizontal connection from furnace, ofcourse after 18 inches of rise from 4" furnace exhaust vent, the Type B goes all the vertical to the roof and then ends with a Thimbled cap. I would need a Type B connection for the 3-4 feet horizontal run from the furnace. Yes the furnace is Cat 1 fan assisted combustion on the natural gas.

Originally Posted by Lon Henderson

Ditto H. G.

There are many thing in a home that DIYer can do, but based on your questions, you absolutely need a professional. We constantly see where smart guys thought they had figured out a common sense "fix", but they end up just figuratively putting lipstick on an alligator, and still have a beast of a problem.
Fork out the dough, and pay a pro to fix your vent.

Or in other words, just follow the manual directions point for point. Only thing is self work might result in little less clean cutting or pasting or gluing type minor stuff.

Originally Posted by NMatts

Or in other words, just follow the manual directions point for point. Only thing is self work might result in little less clean cutting or pasting or gluing type minor stuff.

NO! There should be no cutting, PASTING or GLUING of a B-Vent system!

You NEED a PROFESSIONAL, this is quite evident!

Originally Posted by H.G. Watson, Sr.

NO! There should be no cutting, PASTING or GLUING of a B-Vent system!

You NEED a PROFESSIONAL, this is quite evident!

buddy, i am talking in genenal diy stuff around the house, not the type-b vents or gas connection or electric stuff. thanks for detailed instrctions and concern though, appreciate the inputs.