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    Narataru's Avatar
    Narataru Posts: 28, Reputation: 0
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    #1

    Jul 1, 2009, 11:45 AM
    Attic Bathroom Venting
    How to vent this bathroom if the main stack vent in the house is lower than the bathroom level. Do I need a 2nd vent stack that goes through the roof? This is the plans.
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    speedball1's Avatar
    speedball1 Posts: 29,301, Reputation: 1939
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    #2

    Jul 1, 2009, 12:19 PM
    Is that your only vent? What's venting the downstairs lavatory and tub?
    Narataru's Avatar
    Narataru Posts: 28, Reputation: 0
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    #3

    Jul 1, 2009, 12:50 PM
    This is how the main bathroom is now, I don't know if it's vented or not right now. Thanks.
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    massplumber2008's Avatar
    massplumber2008 Posts: 12,832, Reputation: 1212
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    #4

    Jul 1, 2009, 01:08 PM
    Hi Narataru:

    I have to figure that the main bathroom is piped up (as a minimum) much like I have drawn it below. The dotted lines represent the vents.

    The top floor will need to be vented, again, at a minimum, so that the 2" lavatory vent WET VENTS the toilet, the tub and of course acts as a dry vent for the lavatory itself.

    So, to answer your question... YES, you will need to run a 2" vent through the roof... much like I have drawn below.

    Notice also that I have drawn the top floor waste/vents (in blue) such that it connects BELOW the main bathroom plumbing. If your main toilet uses this stack as a VENT then you will need to connect BELOW the main plumbing as I have drawn it. If your toilet uses its own vent or the lavatory vent as a wet vent then you can connect into the plumbing on the top floor... but you will need to determine that before you can proceed... ;)

    Let us know if you have more questions...

    MARK
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    Narataru's Avatar
    Narataru Posts: 28, Reputation: 0
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    #5

    Jul 2, 2009, 11:23 AM
    Thanks a lot for your help. I'll start my project and hopefully get it ready this weekend. :D
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    Narataru Posts: 28, Reputation: 0
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    #6

    Jul 3, 2009, 06:42 AM
    Hello,
    I was wondering, how to connect the section where the pipe connects to the main stack? That stack is Cast Iron Pipe. Can I add CPVC in that section? Should I drill a hole in the stack?
    Thanks
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    massplumber2008's Avatar
    massplumber2008 Posts: 12,832, Reputation: 1212
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    #7

    Jul 3, 2009, 07:52 AM
    Hi Narataru:

    When cutting into a cast iron stack you need to be concerned about the weight of the piping... Here, you will need to purchase a RISER CLAMP (plumbing supply company) and tighten onto the pipe just above where you intend to cut into the cast iron stack. Then you will support that hanger and the weight of the stack to the floor using 2"x4"x whatever length you need" to get under the ears of the hanger and distribute the weight to the floor...see 1st two images below.

    While at the plumbing supply house getting the riser clamp you will also want to purchase a 4"x3" CAST IRON NO-HUB WYE fitting, 2-4" shielded clamps (cast iron x cast iron... see 3rd image), 1-3" no-hub clamp (4th image), 1-3" no-hub x PVC adapter (transitions from cast iron to PVC) and any other PVC materials (fittings, pipes, hangers, etc) and PVC cement and primer that you think you will need.

    When cutting into the stack be sure to measure the cast iron wye fitting and then add about 5/8" maximum to this length and cut this measure out from the stack. The extra 5/8" is to accommodate the rib in the 2 clamps and to allow for a less than perfect cut on your part. For example, if the wye fitting is 9", you want to remove 9 5/8" from the stack.

    When installing the wye fitting ointo the stack you will want to slide the clamps over the pipe and then install the neoprene sleeves and FLIP them back on themselves to insert the wye fitting into the stack (see bottom image depicting folding of sleeve). Once the fitting is in place and level, flip the neoprene sleeves into place and slide the clamps on and tighten up appropriately.

    Finally, be careful of the weight of the stack on the bottom, too. Be sure that all piping you work with here is supported properly or you could end up with a plumbing disaster, or worse, could hurt yourself... ;)

    Let me know if you have questions...

    MARK
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    massplumber2008's Avatar
    massplumber2008 Posts: 12,832, Reputation: 1212
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    #8

    Jul 3, 2009, 08:10 AM
    You will need a sawzall with long bi-metal blades to cut into the stack. I do not recommend using the chain or snap cutters for these two cuts as they can crush the pipe on occasion. Take your time, make straight cuts and this will go well for you... ;)

    Purchase a few extra blades just in case you have thick cast iron pipe.

    MARK
    Narataru's Avatar
    Narataru Posts: 28, Reputation: 0
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    #9

    Jul 3, 2009, 08:26 AM
    Can I connect Cast Iron to PVC like this, and what kind of joints do I need? Thanks again
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    massplumber2008's Avatar
    massplumber2008 Posts: 12,832, Reputation: 1212
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    #10

    Jul 3, 2009, 08:29 AM
    The plumbing codes that I know of will not allow PVC pipe to be inserted into a cast iron stack like you present... if the weight from the cast iron is too extreme the PVC can shatter... can be quite dangerous and would just cause all plumbing above the break to shatter/crack, break, etc...

    In the long run, I promise you that installing the cast iron wye actually takes less time than PVC... no priming/cementing/cutting small pieces of pipe involved... ;)

    Follow the previous advice... also gave you a list of fittings/materials.

    MARK
    tdcastee1's Avatar
    tdcastee1 Posts: 2, Reputation: 1
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    #11

    Jul 21, 2009, 07:39 AM
    Hi All,

    In my exploration for information, I came across this forum. It seems as though everyone is rather helpful, so I thought I'd give it a shot.

    I'm building a new bathroom on the 2nd floor of my bungalow. In researching the plumbing, I found (I think) that the plumbing is going to be rather tricky. Please check out the picture below. I realize it's not to scale exactly... I'm no artist, but I think the schematic will work??

    In any case, I plan to do this myself and would like to do it right, so before I dive into this thing, I'd appreciate if someone could help point me in the right direction. Thus, my questions are as follows:

    1. Will the Studor vent concept that I propose work here? The trouble is that there is a skylight and chimney and roof vents in the nearby area, so it's tricky, if not impossible, to run vent lines for this group within travelling a large horizontal distance. Given that, I believe a studor vent is the best - or maybe the only - way to go. Thoughts?

    2. Does a Studor vent need to be a minimum distance vertically above all other fixtures? Is it 6" above ? How would this 6" be measured? For instance, if I was measuring above a wall mount toilet, would am I measuring from? The centerline of the horizontal waste exit point of the wall carrier?

    3. As I've drawn, would the wet venting (via sink Studor) for this new wall toilet be acceptable?

    4. Is the existing first floor bathroom group correct? I only ask because now after reading information and living there long enough to know that the sink and tub don't exactly drain fantastic, I don't think it's correct. I believe that the sink & tub, at minimum, need to be revented to the main stack. Could someone please verify? I figure if I'm going to be embarking on this level of a plumbing mission, I might as well fix everything to be correct.

    I certainly would appreciate any help you all could provide. Of course, if you think there are better or easier ways to go about this, please let me know as well. Also, if it helps, all the existing plumbing above the basement floor is PVC and the wet wall that I'm proposing to run the new 3" drain through unfortunately is within 2x4 studs.

    Thanks again,
    Troy
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    massplumber2008's Avatar
    massplumber2008 Posts: 12,832, Reputation: 1212
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    #12

    Jul 21, 2009, 10:00 AM
    Hi Troy...

    Let's start with the fact that the entire 2nd floor is unvented as you said. Would be nice to repipe so vents connect back into the vent stack... should improve drainage.

    The kitchen sink... are you sure there is no vent in the wall? Double check.. OK?

    In terms of the top floor bathroom I don't really like studor vents. I'm willing to bet that there is some way to connect back into the existing vent stack before it goes out the roof... yes..? Let me know... O.K.

    The way you have it now doesn't work, so answer my questions above and I'll see if I can draw something up that will work right!

    MARK
    tdcastee1's Avatar
    tdcastee1 Posts: 2, Reputation: 1
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    #13

    Jul 21, 2009, 11:30 AM
    Mark,

    Thank you for the swift response. My answers/comments to your questions and comments:

    1. I am sure the 1st floor (I think you meant) existing bathroom fixtures are not vented. Are you suggesting these should be revented back into the main vent line? I might be able to do the tub and sink without too much trouble based on what I remember of how the plumbing cuts through the stringers. Should the vents be 1.5" diameter for these devices? The toilet might be ugly though...

    2. I am sure there is no vent for the kitchen sink either. Honestly, I'm not sure there is a good way to get a vent from there up into the attic to retie into the main vent line because the sink has a window right above it (it's on an exterior wall). I'd have to shift over 18" or so inches into the "wet wall" off the 1st floor bathroom to do it. To be honest, this sink doesn't have any draining problems actually so I'm not sure it makes sense depending on the hassle.

    3. I understand what you mean about venting the upstairs off the existing vent line. Actually, my drawing isn't to scale. The new proposed bathroom plumbing is not enough below where the existing vent line pops through the roof; it cannot be tied into this vent. The amount of exposed vent pipe between the 2nd story floor (or 1st floor ceiling) and the roof is maybe 12" inches. To better explain, maybe the shower would be "below" (vertically speaking) the existing vent through the roof, but the sink and wall toilet waste line definately wouldn't be. Given this, what do you propose I do to vent the new 2nd floor bath? A studor vent? Or a new vent line up through the roof? If a new vent up through the roof, what proximity restrictions do I have to dormer vents, roof cap vents, skylights, etc? Also, how much horizontal run in vent lines is allowable ?

    Thanks so much. Looking forward to what you propose. By the way, both quotes I received last week (which were ridiculuously high IMO) proposed the concept I think as I drew it. I know both suggested the studor vent....maybe my joining of the new sink and shower and then that line to the 3" waste off the new toilet was incorrect.

    Troy

    P.S. I live in the Detroit metro area of Michigan.

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