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Thread: vent stack help

  1. #1
    Michael Greenwalt's Avatar
    Michael Greenwalt Guest

    Default vent stack help

    Ok, here is a photo of a waste vent stack on a newly remodeled home. This is the only vent I could find on the structure. The vent exits at the 2nd floor ceiling height, there is a main floor below (with a 1/2 bath) and kitchen sink, and a full bath in the basement. It has a metal roof and the vent size is 2 inches. There are 3 1/2 baths with two tubs, one shower, one kitchen sink, four bathroom sinks, 4 toilets and a laundry room sink.
    Now, the pipe is vertical with a horizontal run soo......

    What I am saying is that in 5 years this is the first one of these I have seen and code is absolutely confusing enough to dis-allow me a competent chance of understanding how much is wrong with this....or isn't.

    Any input? Thanks.

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  2. #2
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    Default Re: vent stack help

    Michael, is that vent pointing down? It also looks like it is capped on the end.

    How was the venting at the plumbing fixtures inside the house? Any gurgling at sinks or tubs and any slow draining water?

    Also, was there any access for the attic interior? Somebody may have run some additional vent lines and never extended them to exhaust to the exterior so they could be emptying into the attic.


  3. #3
    Michael Greenwalt's Avatar
    Michael Greenwalt Guest

    Default Re: vent stack help

    Good question Nick, no gurgling I could tell but I did not run fixtures on multiple floors at one time. The is no attic, 1920's home with drywall attached to rafters on the second floor.

    Yes, the vent is capped, with holes drilled everywhere,,,I did not measure and count holes to determine if they equal 2 inches


  4. #4
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    Default Re: vent stack help

    That one vent pipe with a few holes drilled in it I could not see venting one toilet properly never mind the whole house.

    Are there studer vent under all the sinks, something, anything. I would say it is time for a plumber.

    Ted


  5. #5
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    Default Re: vent stack help

    Michael
    Read IRC 2006; sections 3109 and 3111, then come back and ask anything you want. If you don't have the 2006 IRC you should not be performing home inspections, or whatever code book your local building department has adopted. I donít wish to sound brutal, but that's a fact of life in our profession!

    Jerry McCarthy
    Building Code/ Construction Consultant

  6. #6
    Michael Greenwalt's Avatar
    Michael Greenwalt Guest

    Default Re: vent stack help

    Jerry,
    I have 2006, and 2003, and 2000,,,I have read all the mentioned sections, and more. As a home inspector I am smart enough to know to recommend a plumber get in there to repair it. That doesn't help me understand it. If I understood what I read in the appropriate sections I wouldn't be asking in this forum.
    Thanks for your input, and if you know something that can help a home inspector understand what plumbers pretend to know (a licensed plumber performed the upgrades to the home so I know he is going to come back with WHY this is a correct installation) it would help.

    Thanks


  7. #7
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    Default Re: vent stack help

    All you two guys need is IRC P3103 if you are relating the answer to the photo - the vent terminal.

    From the 2006 IRC. (bold and underlining are mine)
    - SECTION P3103
    - - VENT TERMINALS
    - - - P3103.1 Roof extension. Open vent pipes that extend through a roof shall be terminated at least 6 inches (152 mm) above the roof or 6 inches (152 mm) above the anticipated snow accumulation, whichever is greater, except that where a roof is to be used for any purpose other than weather protection, the vent extension shall be run at least 7 feet (2134 mm)above the roof.
    - - - P3103.2 Frost closure. Where the 97.5-percent value for outside design temperature is 0°F (-18°C) or less, every vent extension through a roof or wall shall be a minimum of 3 inches (76 mm) in diameter. Any increase in the size of the vent shall be made inside the structure a minimum of 1 foot (305 mm) below the roof or inside the wall.
    - - - P3103.3 Flashings and sealing. The juncture of each vent pipe with the roof line shall be made water tight by an approved flashing. Vent extensions in walls and soffits shall be made weather tight by caulking.
    - - - P3103.4 Prohibited use. Vent terminals shall not be used as a flag pole or to support flag poles, TV aerials, or similar items, except when the piping has been anchored in an approved manner.
    - - - P3103.5 Location of vent terminal. An open vent terminal from a drainage system shall not be located less than 4 feet (1219 mm) directly beneath any door, openable window, or other air intake opening of the building or of an adjacent building, nor shall any such vent terminal be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 2 feet (610 mm) above the top of such opening.
    - - - P3103.6 Extension through the wall.Vent terminals extending through the wall shall terminate a minimum of 10 feet (3048 mm) from the lot line and 10 feet (3048 mm) above the highest adjacent grade within 10 feet (3048 mm) horizontally of the vent terminal. Vent terminals shall not terminate under the overhang of a structure with soffit vents. Side wall vent terminals shall be protected to prevent birds or rodents from entering or blocking the vent opening.

    First A, the "vent terminal" must then also meet P3103.5 Location of vent terminal.
    First B, vents with an extension through the wall must meet P3103.6 Extension through the wall.

    - [Note that First B 'Extension through the wall' is of secondary importance to First A only in that it has "additional requirements" over First A (which is typically the only one of the two applied as most vent terminals 'roof extensions' and not 'wall extensions').]

    Second, the vent must also meet 3103.2 Frost closure (if in the area described by the temperature limitation).

    Followed by the lesser important (to that photo): P3103.3 Flashings and sealing, and, P3103.4 Prohibited use.

    That vent extension through the wall *DOES NOT MEET* 'P3103.5 Location of vent terminal' or 'P3103.6 Extension through the wall, and I don't know if the '3103.2 Frost closure' section applies.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  8. #8
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    Default Re: vent stack help

    Yeah what the Jerry's said


    Like I said in short because for some reason or other I don't have computer copies of the code on my computer (Hmmm, I've been going to forever)

    Something, some where there has to be vents you missed. I just don't see how any of the home has been draining with zero vents, more than likely sucking traps dry around the home.

    Well, one upside down pipe with a cap and a few holes drilled in it.

    Ted


  9. #9
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    Default Re: vent stack help

    Just out of curiosity is the "outside design temperature" I see in charts the same as the "97.5-percent value for outside design temperature" in the codes?


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  10. #10
    Michael Greenwalt's Avatar
    Michael Greenwalt Guest

    Default Re: vent stack help

    Thanks all,
    Appreciated.

    Round these parts it's do what U want or can get away with. The IRC is used more as a paperweight than a reference. And believe me our builders get away with a lot. Incidentally, we have 22 new homes that are under threat of being condemed, about $3M worth and more potential candidates are out there. I call it criminal, our city councils call it growing pains. Guess it depends on which side of the payment your on.


  11. #11
    Joshua Hardesty's Avatar
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    Default Re: vent stack help

    Vents are allowed to exit the side of the building provided the follow the codes Jerry laid out.

    It appears they tried to "bird-proof" the vent by putting the pipe with the holes drilled in it. However I can't imagine it would allow the same airflow that an open 2" pipe would provide; and furthermore, they sell coverings for pipes to be used in such an occasion.


  12. #12
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    Default Re: vent stack help

    Quote Originally Posted by Michael Thomas View Post
    is the "outside design temperature" I see in charts the same as the "97.5-percent value for outside design temperature" in the codes?
    Michael,

    No, go the IPC, Appendix D, there is a column under 'Design Temperatures', the 'Winter' column is below it, with the '97-/12%' column below it.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  13. #13
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    Default Re: vent stack help

    Quote Originally Posted by Jerry Peck View Post
    P3103.6 Extension through the wall.[/COLOR][/SIZE][/FONT]Vent terminals extending through the wall shall terminate a minimum of 10 feet (3048 mm) from the lot line and 10 feet (3048 mm) above the highest adjacent grade within 10 feet (3048 mm) horizontally of the vent terminal. Vent terminals shall not terminate under the overhang of a structure with soffit vents. Side wall vent terminals shall be protected to prevent birds or rodents from entering or blocking the vent opening.

    That vent extension through the wall *DOES NOT MEET* 'P3103.5 Location of vent terminal' or 'P3103.6 Extension through the wall, and I don't know if the '3103.2 Frost closure' section applies.
    Jerry,

    How can you tell from the photo and description that it doesn't meet P3103.6? We don't know where the lot line is so the first requirement of P3103.6 is unknown. We do know it exits the building at the ceiling height of the second floor which meets the second requirement (unless the first floor is garden level or the grade is on a steep incline). From that picture I couldn't see any soffit vents so that requirement also seems seems met or at worst unknown to me. The orientation, location, and creative use of a cap and drill also seem to meet the last requirement (although it appears to violate the vent sizing requirement).

    Sure, the vent still gets a failing grade but I'm not perceptive enough to see how it fails P3103.6. Let me know what I'm missing or not noticing.


  14. #14
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    Default Re: vent stack help

    Quote Originally Posted by Jerry Peck View Post
    P3103.6 Extension through the wall.Vent terminals extending through the wall shall terminate a minimum of 10 feet (3048 mm) from the lot line and 10 feet (3048 mm) above the highest adjacent grade within 10 feet (3048 mm) horizontally of the vent terminal. Vent terminals shall not terminate under the overhang of a structure with soffit vents. Side wall vent terminals shall be protected to prevent birds or rodents from entering or blocking the vent opening.

    That vent extension through the wall *DOES NOT MEET* 'P3103.5 Location of vent terminal' or 'P3103.6 Extension through the wall, and I don't know if the '3103.2 Frost closure' section applies.
    Quote Originally Posted by Corn Walker View Post
    Jerry,

    How can you tell from the photo and description that it doesn't meet P3103.6?

    From that picture I couldn't see any soffit vents so that requirement also seems seems met or at worst unknown to me.
    Oops, ... big time oops ... even though I highlighted it with bold, *I* *missed* the "with soffit vents" part of the "shall not terminate under overhang".

    Sure, the vent still gets a failing grade but I'm not perceptive enough to see how it fails P3103.6. Let me know what I'm missing or not noticing.
    Not you missing something, it was me, regarding P3103.6.

    However, the vent turns down, not up.

    Let's suppose the vent did turn up, the vent may not be reduced in size (per the code). They would have to have *a lot* of holes to meet the effective area of the vent.

    Let's "guess" that it is a 2" vent (based on the respective size of that dryer vent - could be a bath fan too), that means it area is approximately 3.14159 sq inches. Let's "guess" that those holes are 1/8", which makes each hole approximately 0.01227 sq inches. 3.14159 / 0.01227 = 256 holes. I count 15 holes up that one line which is best visible, I see what appears to be another line of holes about 90 degrees over to the right, so I'll presume there are potentially 4 columns of 15 holes for 60 holes, give or take.

    Nonetheless, that does not take away from my big oops with missing the soffit vent part.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  15. #15
    Patrick Martinez's Avatar
    Patrick Martinez Guest

    Default Re: vent stack help

    Hi Fellas,

    seeing this setup, and if it is indeed a vent, it is not meeting cross sectional area of the drain. Given that you have 24 DFU's, 3" piping will handle the load. Based on 3" pipe, the vent cross section for two inch piping is sufficient. However !! Seeing the cap in the piping, it has reduced the cross section well below the vent FU's requirement. Not to mention, the down turn of the line basically will not permit the free flow of air into the system.

    You mention a basement bathroom, is there a sump serving the basement?
    If so, it should be separately vented in its entirety. This makes me think it could be a vent for the sump alone. However, you mention you did not find any other vents....HHMMMMmmmm???

    The vent you pic does not permit free flowing air, it actually traps air. Surprising you did not find bigger drainage issues.

    Michael, I hope this helps. Good luck!

    Pat


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