p-trap location Changing from wall hung sink to vanity sink

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by k9mlxj, Oct 21, 2011.

  1. k9mlxj

    k9mlxj Member

    Messages:
    104
    Location:
    Bay Area CA
    p-trap location - Changing from wall hung sink to vanity sink

    Hi folks,

    Here's another plumbing issue I'm coming across.


    I had a wall hung sink in the bathroom that was there probably for a long time. I am installing a vanity sink instead.


    With the vanity sink I purchased, the location of the p-trap's outlet would roughly be around 7" from the wall. The old outlet tube would meet the p-trap's outlet at 3" (measured from the wall). So the new p-trap won't meet this tube.


    Old wall-hung sink - outlet tube:

    Bathroom - p-trap outlet tube.jpg


    How do I make up for the difference to connect to the new p-trap then? Would I need to remove this outlet tube since it won't match up to the new p-trap from the vanity sink location?


    Anyone would have any suggestion:

    - if there's a way to hook up to the new vanity sink's p-trap - to make up for the difference of the location
    (4" difference)

    - if need to remove this old tube, how to go about doing it?
    (Note: the CI elbow is in the wall...)



    A close-up of the connection to the CI-elbow. It seems the tube was 'glued' to the CI elbow?
    (It's pretty tight...)

    Bathroom - p-trap outlet tube - close-up.jpg



    BTW, in our 2nd bathroom, this is how the new p-trap was installed (by the installer):

    Bathroom 2 - p-trap.jpg


    Looks like the p-trap was installed the opposite way so to allow for an elbow to match up for the location of the new flange from the vanity sink. Perhaps the installer didn't want to remove the old tube.


    Is this an acceptable way of installing the p-trap? (Or someone'd be real upset when seeing this...)



    If not, let me know so I might as well fix it up also... .


    Thx.
    Last edited: Oct 21, 2011
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,129
    Location:
    New England
    Can't tell for sure, but it sort of looks like it was leaded into the pipe in the wall. that piece is part of the trap of the old one, and needs to be removed - maybe peeled out. Normally, the trap arm would then slide into a Desanko which would have enough length to accommodate your new sink. I think you'll need to remove that piece, clean up what I think is a threaded connection, and then you could adapt the new drain parts to that. Wait for one of the pros to set us both straight.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,815
    Location:
    Cave Creek, Arizona
    It is a brass solder bushing. You have to chop the tubing out of it, the cut it out of the fitting. Then you can do whatever you need to in order to connect the trap to the new sink. Just do NOT do it the way it was connected previously. It was NOT done by anyone who knew something about sink drains, that is for sure. Do you have ANY sink drains which were installed correctly?
    Last edited: Oct 21, 2011
  4. k9mlxj

    k9mlxj Member

    Messages:
    104
    Location:
    Bay Area CA
    The brass solder bushing permanently binds the pipe to the bushing. And this makes it so hard to make any changes. Why would someone make this kind of connection... (they think the p-trap pipe would never need to be changed I suppose?)


    BTW,

    - Don't understand anything about this solder bushing -- Was the bushing threaded into the CI elbow? If so, can I just turn the pipe anti-clockwise to unthread it and the bushing out of the elbow? Or it was soldered to the CI elbow?


    - was it lead that the chrome pipe was soldered to? I wonder if I can use MAP gas torch and heat it up til' I can move the pipe out?

    Would applying heat causing any damage to the rest of the CI elbow's joint? And the wall?


    And after that -- how'd I remove the bushing -- use a cold chisel to cut it out?



    These two bathrooms sink pipes both have these brass solder bushings. Headache... .
    Last edited: Oct 21, 2011
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,129
    Location:
    New England
    One of the pros may have a better way, but I'd hack saw it off, then saw through the brass sleeve from the inside in a couple of places, then peel it out. You might be able to heat it up enough to pull it out without burning down the house...can't say, don't know.
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,815
    Location:
    Cave Creek, Arizona
    quote; Why would someone make this kind of connection... (they think the p-trap pipe would never need to be changed I suppose?)

    In "unionized areas", such as NYC, Chicago, and the Bay Area, solder bushings are required for several reasons.
    1. It takes longer to install it.
    2. The installer has to be experienced, and most important,
    3. It makes it DIFFICULT or IMPOSSIBLE for the homeowner to repair it himself.

    The solder bushing and trap were preassembled, and then screwed into the fitting. Over time corrosion and age have made it IMPOSSIBLE to unscrew using just the trap's pipe. It WILL twist and deform but will NOT unscrew. Applying heat to it, MAY let it come out, but more likely there is a buildup on the part exposed INSIDE the pipe so it will be too large to slide out. You could also start a fire in the wall and burn the house down.
  7. k9mlxj

    k9mlxj Member

    Messages:
    104
    Location:
    Bay Area CA
    Thought perhaps I could open up the wall a bit more and heat it up so can turn it loose... . Just need to surround the area w/ sheet metals to protect the area around it, then heat it up enough just to loosen the pipe (dry wall repair is fairly easy thing to do... the area around the dry wall is fairly open now).


    But looks like it's going to be a painful process to cut it out carefully w/o cutting into the threads in the elbow... .

    Now I know why the installer didn't bother to change it out... .


    Still don't understand -- any 'practically beneficial' reason it was required that way (besides the political one)?


    So it's ok to change out to a Desanko fitting?
    Last edited: Oct 22, 2011
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,129
    Location:
    New England
    A soldered/leaded connection is more robust than one made with compression fittings, but likely equivalent to solvent welded ones (but that means plastic verses metal fittings). In some situations, mostly high-rise buildings, plastic drain pipe and fittings aren't used to prevent a fire hazard. If you've got a union friendly rules group...the one that takes the most skill and time is likely to win in the regulations, but doesn't necessarily have more merit.
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