Professional opinions on this plumbing job, please.

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Kimster, Aug 16, 2010.

  1. Tom Sawyer

    Tom Sawyer In the Trades

    Joined:
    Nov 29, 2010
    Location:
    Maine
    There are no code approved methods for gluing PVC to ABS. Glue joints on similar piping are a solvent weld which means that the pipe and fitting have been fused. PVC and ABS are incompatable plastics and no glue will solvent weld them. The only approved methods of joining the two are by use of Fernco or mission band couplings or a male/female threaded connection.
     
  2. nukeman

    nukeman Nuclear Engineer

    Joined:
    Nov 20, 2009
    Occupation:
    Nuclear Engineer
    Location:
    VA
  3. Kimster

    Kimster Member

    Joined:
    Jul 9, 2010
    Location:
    Manitoba
    Nukeman, that's such a nice offer. I'm going to call the remaining two plumbing supply shops here and if I don't have any luck, I'll take you up on it.

    JM, the PVC vs ABS issue, I think, would make things more convoluted. I don't know if our inspectors would pass that, so I think I'll keep at the ABS. There has to be a reason no one here carries this "medium" sweep. I suspect that whatever is sold at HD -- the short sweep is acceptable to the inspectors, but sometimes that still isn't the best practice. I did happen to look at my newer plumbing in the basement (circa '80s) and they did, in fact, use the medium turn ells.
     
  4. Tom Sawyer

    Tom Sawyer In the Trades

    Joined:
    Nov 29, 2010
    Location:
    Maine
    The 90 degree fittings sold at most big box stores are medium sweep.
     
  5. Kimster

    Kimster Member

    Joined:
    Jul 9, 2010
    Location:
    Manitoba
    AHA!!

    Just got off the phone with NIBCO Canada. Apparently, except for British Columbia, all other provinces, when using a 1 1/2 fitting in DWV to code, needs to be a short radius. That's why the HD online shows they have the product, but it isn't available here. They carry it for BC. The fitting 5807SR is actually a product specifically made for Canada and stands for 5807shortRadius.

    So, for us here, I actually DO have the right part. So, I hope that, just because it didn't totally bottom out near the back when I glued it, it'll still be OK and won't leak because I'd rather not have to redo it. It really doesn't make sense to me, though, why we wouldn't be using a med. sweep for ease of cleaning. Maybe they figure junk should get trapped in the elbow closest to the trap. I don't know.

    See, a few phone calls and there you go. On to more framing and finishing the rough plumbing...

    Thanks so much for all your help everyone. I'm sure I'll be calling on your experience again.
     
  6. JMThomas

    JMThomas New Member

    Joined:
    Sep 17, 2009
    Location:
    Indianapolis
    My wife, the chemist, says that the magic word is "co-solvent".

    Looking at the MSDS, she says that they are probably hooking the ABS and PVS to a third item. She says tetrahydrofuran is a polar ether which will connect to dissimilar materials, and notes that the cyclohexane based molecule may also be part of the scaffolding between the ABS and PVC. She also makes disclaimers of "not really her field" and "long time out of school".

    Thus there isn't a direct connection of ABS to the PVC, but PCV to tetrahydrofuran and/or cyclohexanone and then that to ABS.
     
  7. Kimster

    Kimster Member

    Joined:
    Jul 9, 2010
    Location:
    Manitoba
    Hmmm. Maybe there's a business opportunity in that statement?
     
  8. Tom Sawyer

    Tom Sawyer In the Trades

    Joined:
    Nov 29, 2010
    Location:
    Maine
    Yes, it is a "glue" and the bond is dependent on the glue alone. In a solvent welded joint there is no separation between the pipe and the fitting is done properly. They become one single part.
     
  9. ballvalve

    ballvalve General Engineering Contractor

    Joined:
    Dec 28, 2009
    Occupation:
    "retired" and still building and troubleshooting
    Location:
    northfork, california
    http://www.herchem.com/specs/pipecement.pdf

    there are transition cements for low or no pressure - seems to qualify for sewer. And there is a multi purpose cement for abs and pvc for pressure but not meant to join the two variations.
     
  10. ballvalve

    ballvalve General Engineering Contractor

    Joined:
    Dec 28, 2009
    Occupation:
    "retired" and still building and troubleshooting
    Location:
    northfork, california
    http://www.herchem.com/specs/pipecement.pdf

    there are transition cements for low or no pressure - seems to qualify for sewer. And there is a multi purpose cement for abs and pvc for pressure but not meant to join the two variations.
     
  11. JMThomas

    JMThomas New Member

    Joined:
    Sep 17, 2009
    Location:
    Indianapolis
    Yes.

    The confusion is that some universal cements, now labeled "multi-purpose cement", used to have a label saying "ABS-PVC-CPVC Cement" (e.g. old Oatey Red Label).

    This old label implied that it would bond unlike to unlike (e.g. ABS to PVC) which is not true. It merely contained a selection of ingredients so that you could welding ABS to ABS, OR weld PVC to PVC, OR weld CPVC to CPVC. As long as your parts were made of the SAME material, this one cement would do the job.

    Now the manufactures have relabeled the universal cement as "multi-purpose" to discourage the label from giving the blatant idea that it can weld mixed materials. Good for them. As many have said, the product doesn't work on mixed materials.

    To avoid failure from multi-purpose cement on unlike materials, codes were modified to prohibit gluing/welding/cementing ABS to PVC/CPVC. At the time this covered the condition, because nothing worked to chemically join these unlike materials.

    As times change, we find that innovation develops exceptions to wholesale prohibitions. In this case, agents that can successfully fasten ABS to PVC have been developed and been approved for use in non-pressure lines.

    They work. They're proven. They're listed by the UPC and NSF as acceptable.

    But they are getting caught in the blanket prohibition created years ago. Inspectors see an ABS part next to a PVC part and immediately assume that they are fasten with old non-transition cement. They quote the blanket restriction from their local code prohibiting any cemented connection.

    Legally, they are correct. Technically, they are behind the times, and are stopping the advance of technology.
     
    Last edited: Jul 20, 2011
  12. Tom Sawyer

    Tom Sawyer In the Trades

    Joined:
    Nov 29, 2010
    Location:
    Maine
    So........if this glue will solvent weld ABS to PVC then why only under no pressure conditions? Hmmmmmmm
     
  13. Kimster

    Kimster Member

    Joined:
    Jul 9, 2010
    Location:
    Manitoba
    All very interesting information, guys. Good segue for my next rudimentary question:

    If the ABS glue actually welds two of the same type of pipes together, am I to assume that if an ABS to ABS joint doesn't leak when tested, even if the fitting didn't bottom out perfectly, that it won't be likely to leak?

    Also, how, exactly do you test the drain/waste lines for water-tightness and at what point do you do it? After the trap is assembled?
     
  14. JMThomas

    JMThomas New Member

    Joined:
    Sep 17, 2009
    Location:
    Indianapolis
    A water test is done when everything's complete, including your trap/sink connections.

    All openings are plugged, from lowest to highest, starting with the connection from house to the sewer. One method is to insert an inflatable balloon through a main sewer clean-out just outside the house into the main sewer line from the house. The balloon is inflated until it make a tight plug inside the pipe to seal it. There are also stoppers/rubber plugs that can be inserted in many openings like drains, washer stand pipe, etc.

    Then the system is filled with water. Working up floor by floor and level by level is easiest, adding water after verifying that everything at the previous level is sealed. If you really want, plug the last openings and fill the vents up on the roof.

    After a good examination (take a box of facial tissues and wipe each joint), and long wait to see if the water level decreases at all, declare your result.


    You might be lucky and have a clean-out at the bottom of your "stack" which will would allow you to place a balloon into the base of the vertical pipe before it enters the sewer (main) line. Filling the sink with water should get the level above the sanitary tee fed by the drain from the sink. That tee is the highest place you've cut and glued, I believe, so you'd have everything new filled with water for your test.
     
    Last edited: Jul 21, 2011
  15. JMThomas

    JMThomas New Member

    Joined:
    Sep 17, 2009
    Location:
    Indianapolis
    A lot of things in life are evolutionary, not revolutionary.

    PS: It's not a solvent weld in the traditional sense. The label "cement" is very apt.
     
  16. JMThomas

    JMThomas New Member

    Joined:
    Sep 17, 2009
    Location:
    Indianapolis
    The joint will be as mechanically strong as the surface area in (direct) contact between each piece. Since you've no pressure in a waste drain, mechanical strength is not near as great a consideration as for water supply lines.

    Many connections are deliberately NOT perfectly bottomed out. One side of the pipe is slightly away from the bottom of the fitting so that the pipe does not come out perfectly straight. This is how the small downward slope is created, such as with your horizontal drain line.

    This is my personal opinion now: if you're at least 1/2 way in, you're fine for DWV lines. I'll gladly accept education here...
     
    Last edited: Jul 21, 2011
  17. Tom Sawyer

    Tom Sawyer In the Trades

    Joined:
    Nov 29, 2010
    Location:
    Maine
    Just to wrap this glue thing up. Transition glues are not acceptable by code for either pressure or non pressure lines. If the joint is not solvent welded it will eventually fail due to expansion and contraction of the pipe. There is no evolution here whatsoever. No solvent weld, not code accepted.

    All joints need to be bottomed out. Slope is achieved by proper hanging or support methods, the fitting should never be used to achieve grade.
     
  18. Kimster

    Kimster Member

    Joined:
    Jul 9, 2010
    Location:
    Manitoba
    Thanks Tom. I wasn't intentionally trying to create slope there, but because of the way the stack is situated (it was installed crooked from the bathroom floor up through the roof), in the wall, I could only get the new ABS section with the new drain arm so far into the 2x4 wall. In order to get the 90 that will go to the trap level, I couldn't bottom out the backside of the 90 otherwise, the section of pipe that would be going into it would be crooked as all hell and wouldn't line up with anything.

    Is there a reason why, if the sections are welded together by the glue, that if it doesn't leak, it has to bottom out? Is this for ease of cleaning?

    Thanks.

    JM, I had no idea a water test was that complicated. I have to say, it's a pretty extreme test because those aren't normal conditions. I mean, when would your entire waste system hold water under pressure? It's only ever really handling running water. Wouldn't just running water through each connection approximate real life?
     
    Last edited: Jul 21, 2011
  19. Tom Sawyer

    Tom Sawyer In the Trades

    Joined:
    Nov 29, 2010
    Location:
    Maine
    All codes say that the pipe must be fully inserted into the fitting and that's logical because who is going to determine just how much it can be off? Is 1/2 way enough? how about 1/4" The other reason for full insertion is that as the pipe bottoms in the fitting it creates a smooth transition through that fitting with no ledge ( end of the pipe ) not fully inserting it can cause stuff to collect and plug the fitting.
     
  20. Kimster

    Kimster Member

    Joined:
    Jul 9, 2010
    Location:
    Manitoba
    Okey-doke. Makes sense.
     
Similar Threads: Professional opinions
Forum Title Date
Plumbing Forum, Professional & DIY Advice DIY HOMEOWNER... could use professional opinions on copper and roots ? Oct 21, 2010
Plumbing Forum, Professional & DIY Advice some professional opinions please. Mar 21, 2007
Plumbing Forum, Professional & DIY Advice Need some professional opinions Nov 22, 2005
Plumbing Forum, Professional & DIY Advice Input on professional furnace/tankless water heater install (bad work) Mar 26, 2020
Plumbing Forum, Professional & DIY Advice Boiler Fault Finder For the Professional Heating Engineer Jan 8, 2019

Share This Page