Big basement bathroom project

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by fiasco, Nov 14, 2005.

  1. fiasco

    fiasco New Member

    Messages:
    43
    I have a narrow basement. The bathroom currently sits square in the middle wasting space for what could be a very usable room. Meanwhile, I have wasted space at the other end of the basement where I want to put the bathroom instead (where the washer and dryer are).

    I have included two rough diagrams (not to scale)

    The existing 3" flloor/vent stack/sewer line are shown. A 2" vent will cross the ceiling for 10' and then turn and travel 8' to the existing 3" vent stack. It will be attached to the vent stack above the highest drain connection.

    For the vent stacks servicing the new bathroom, do I need to put a third for the toilet or will the two branches serving the sink and tub be sufficient?

    The existing sewer line is 2 1/2' below the foundation. The new run will drop 4" over the 16' run. It won't connect to the floor drain as it appears in the rough diagram. That drain is actually offset from the sewer line.

    My big concern is the 90 deg in the sewer for the new bathroom. Is this acceptable? Is there a better solution to turn that corner?

    [​IMG]
    [​IMG]
    Last edited: Nov 14, 2005
  2. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    As far as the 90 goes bust up more of the floor and use 2 - 45s with at least 2' of pipe between them. When you say "The existing sewer line is 2 1/2' below the foundation." do you mean the floor or the footer can you be more specific?
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,534
    Location:
    Cave Creek, Arizona
    pipes

    A plumber would simplify the layout by using a long radius elbow at the turn and also below the toilet connection, then he would use a 3x2 side inlet tee for the toilet and bathtub/shower with the 2" going to the P trap. Then the lavatory/sink would connect to a T in the toilet's 2" vent line and then the single vent would connect back to the 3" above all the other connections, which means it would be at least 42" above the floor in the first floor wall. You would also need a 3" cleanout in the pipe above the floor behind the toilet.
  4. Bob NH

    Bob NH In the Trades

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    3,317
    Location:
    New Hampshire
    You will save about 4 ft of breaking concrete if you run the sewer line diagonally.
  5. fiasco

    fiasco New Member

    Messages:
    43
    Cass,

    I was planning on using two 45's to soften that elbow. i wish I could go diagonaly but that would require moving the furnace. The sewer pipe is 2 1/2' below the top of the floor.

    HJ,

    I gather from your description that something like what is in the attached image will be ok?

    Attached Files:

  6. fiasco

    fiasco New Member

    Messages:
    43
    Or, would this be acceptable? This would be easiest because it' will be difficult to get the new 2" vent line coming out of the floor close to the wall. I'd be able to hide it more effectively behind the tub installation.

    Attached Files:

  7. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    I hope you mean 2 1/2" from the bottom of the floor because most floors are 4" thick. Even still unless I'm not getting something right where you make your tie in the existing line will be higher than where the run ends. Am I not understanding you right? If I do get you right you will need an ejection pump and pit.
    Last edited: Nov 14, 2005
  8. fiasco

    fiasco New Member

    Messages:
    43
    The sewer drain is approximately 2 1/2' (feet) below the top of the floor where it exits the house and that is where I will be tieing in.

    is the vent pipe diagram I last posted acceptable?

    Lastly, when I repour the cement I don't want the slab settling. Can I drill pilot holes in my cut edges and insert some short rebar (spelling?) to support the new cement?

    I'm still in demo mode right now. I have most of the trenches cut in the foundation and have broken up the cement and carted it away. I'll be posting pictures of my bathroom project as I progress. Home demo is always tough because I have to account for the WAF (wife acceptance factor)!

    I do truly appreciate all of your advice!
    Last edited: Nov 14, 2005
  9. fiasco

    fiasco New Member

    Messages:
    43
    OK found an answer to my rebar question and pilot holes for rebar dowels. :D
  10. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,534
    Location:
    Cave Creek, Arizona
    Its going to have to be "close to the wall" somewhere, why would it be difficult behind the toilet? That drawing makes the lavatory arm too long. I don't want to take the time to do a new drawing, but if I were doing it, the tee would be in the floor under the new wall behind the toilet, and the tub would go into the side of it with the toilet's closet bend into the 3" opening. Then the vent would go vertical with the tee for the lavatory at the proper height, then a 3" cleanout about 36" above the floor with a 2" bushing in the top of it. There are a few of "good" ways to install your layout, and hundreds of "bad" ways that look easier. Your job is to separate them and pick the best one for you.
  11. fiasco

    fiasco New Member

    Messages:
    43
    HJ,

    Again, I really appreciate the input. I am still in demo mode, got to move the washer dryer, water softener and water heater so I can get to the existing sewer run.

    I just installed Visio so I will post some actual plans instead of stick drawings probably later tonight.
  12. PEW

    PEW DIY Senior Member

    Messages:
    487
    Rebar dowels are probably a bit overkill for a basement floor. Compact the dirt well when back filling.

    When we use rebar dowels in larger commercial applications, we epoxy one end in the existing slab and grease the other so it does not adhere.

    Paul
  13. dubldare

    dubldare Plumber/Gasfitter

    Messages:
    286
    Location:
    MN/ND
    Here's how I'd do it.

    Attached Files:

  14. fiasco

    fiasco New Member

    Messages:
    43
    Here is the floorplan layout. I'll post plumbing diagrams later tonight.

    [​IMG]
  15. fiasco

    fiasco New Member

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    43
    Is there a specific "schedule" PVC pipe that must be used for DWV?
  16. fiasco

    fiasco New Member

    Messages:
    43
    I have all my trenches cut and dug up the sewer line I'm going to join into. Fortune smiles on me as the existing sewer line is 45 deg to my new run so a wye is gonna fit in there just right :D

    I'm getting ready to dry fit all my plumbing. I'll take some photos shortly for your approval/dissapproval.

    Can I use a low heel elbow under the toilet and use the 2" joint off of it for my vent? Also, can I use a 2" vent up from the floor from the toilet or does it have to be 3"?

    If I can't use a low heel 90 under the toilet can I throw a second wye (see pix below) facing the same direction as the pictured one (cement not cut to go the other way) to lead to the wall wet vent stack/sink drain? If I should use a wye, is there a code specifiied minimum distance it must be from the toilet elbow?

    I do not have room to throw a T on top of the toilet elbow for a vent.

    Thanks guys!
    Last edited: Nov 16, 2005
  17. fiasco

    fiasco New Member

    Messages:
    43
    sewer line (flows right to left)
    [​IMG]

    45 deg cut to transition a turn
    [​IMG]

    overall plumbing, the cleanout will be accessed through a panel on the backside of the wall.
    [​IMG]
  18. fiasco

    fiasco New Member

    Messages:
    43
    Toilet hookup (is a low heel 45 ok like this?)
    [​IMG]

    bath hookup
    [​IMG]

    sink
    [​IMG]
  19. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,534
    Location:
    Cave Creek, Arizona
    fittings

    You are confused. You are using "T"s where you should have combination Y-1/8 bends and vice versa. You cannot use a tee, (and a heel inlet elbow is really a tee), for the tub or toilet or vent for the sink. You can use a tee for the connection to the vertical pipe. That sewer line, if it is the one you were referring to appears to be a lot less than 2 1/2', (30"), below the concrete.

    [​IMG]
    This fitting vents off the top.
    Last edited by a moderator: Dec 26, 2008
  20. fiasco

    fiasco New Member

    Messages:
    43
    That line is 13" below the top of the floor. I guestimated the depth of the sewer line exiting the house based on the depth of the P trap on the floor drain, so at the toilet/bathroom area I only have 5" of space to work w/ between the top of the horz pipes and the bottom of the 4" concrete. (accounting for the needed 4" drop over the run of the pipe to the sewer)

    With the close fixtures (tub drain is about 30" from toilet, sink drain is about 34" in from toilet) do I need a seperate vent for each fixture or is that overkill. Could I use an additional wye in the sewer run before the toilet and run that up the wall for the vent?

    I'm anal about getting this right so I appreaciate your help HJ.
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