Sink drain outlet in wall is too low

Reply

  #1  
Old 10-31-13, 05:28 PM
F
Member
Thread Starter
Join Date: Oct 2008
Location: US
Posts: 142
Received 0 Votes on 0 Posts
Sink drain outlet in wall is too low

I'm about to hook up the sink tailpiece and P-trap, but ran into something puzzling because the plumber made the drain pipe exit the wall pretty low, so it ended up only 2.5" from the cabinet floor. That means there is not enough space for me to connect it with the traditional looking P-trap with a straight pipe into the wall configuration. I can do something that looks like an S-configuration with a couple 45s after it comes out of the wall, to raise the height of the P-trap so the bottom of the P-trap is at the same level as the wall pipe (I doubt that would siphon with equal height).. but I think the code requires the P-trap a minimum distance from the cabinet bottom? I'm trying to avoid having to notch the bottom of the cabinet, install some funky air admittance device, or break open the wall to raise the pipe coming out of the wall.

Update: Here is an idea I came up with, not glued yet. What if I rotate the P-trap as in this photo? Does anyone see any problem with rotating the P-trap like this to make enough clearance to the cabinet floor?

Name:  p-trap.jpg
Views: 21768
Size:  24.0 KB
 

Last edited by flyingpolarbear; 10-31-13 at 06:17 PM.
Sponsored Links
  #2  
Old 10-31-13, 06:31 PM
J
Banned. Rule And/Or Policy Violation
Join Date: Apr 2013
Location: USA
Posts: 4,297
Received 0 Votes on 0 Posts
Trap will not work that way, it also may leak. Traps should not be glued in place.
Is this new construction?
It looks like he screwed that up as well as put it in at an angle.
The best way is going to be to open up the wall and fix it.
 
  #3  
Old 10-31-13, 06:43 PM
F
Member
Thread Starter
Join Date: Oct 2008
Location: US
Posts: 142
Received 0 Votes on 0 Posts
The plumber only put the drain outlets in the wall (he's not doing the rest of the sink plumbing). The P-trap at an angle is my idea, and this shows a loose fit, no glue yet. So is the problem that the union may leak because there is always water against it, and P-trap seals were only designed for occasional water?
 
  #4  
Old 10-31-13, 06:52 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
Joe meant you shouldn't use glued traps. You need to open the wall and redo where the trap comes out then use a trap like this:

Name:  7503.jpg
Views: 25060
Size:  9.8 KB
 
  #5  
Old 10-31-13, 06:54 PM
J
Banned. Rule And/Or Policy Violation
Join Date: Apr 2013
Location: USA
Posts: 4,297
Received 0 Votes on 0 Posts
The whole idea of a trap is to keep it full of water, no water and the sewer gas comes in.
I worded my reply wrong, it should have been something like the trap may siphon back into the drain like that. Not leak in as leaking water out of the trap under the sink.
•Drain Pipe: About 16-20 inches above floor. We will consider the drain pipe to be a vertical centerline.
•Supply Lines: Two holes. One hole is 4 inches to the right of centerline, another hole is 4 inches to the left of centerline Vertically, both holes are about 2-3 inches above the drain pipe.
•Placement of Sink: Vertically, the sink should be about 31 inches above the floor. Measure up to the rim of the sink.
 
  #6  
Old 10-31-13, 06:58 PM
J
Banned. Rule And/Or Policy Violation
Join Date: Apr 2013
Location: USA
Posts: 4,297
Received 0 Votes on 0 Posts
Drains plug up most often right in that easy to get to trap.
If it's glued your in deep dodo trying to clean it out.
 
  #7  
Old 10-31-13, 07:54 PM
F
Member
Thread Starter
Join Date: Oct 2008
Location: US
Posts: 142
Received 0 Votes on 0 Posts
The trap in the photo would have a trap adapter at the top with a slip tail going into it, so the entire P-trap can be removed. In Ray's picture the difference is that the trap tailpiece that goes into the wall can also be removed. Is the reason for that removable tailpiece in case someone wants to change the entire assembly out with a different kind of trap in the future (different material, orientation, etc)? Or some code reason?

I may have to break open the wall. This is a perfect example why I am tired of contractors. Even with 20 years experience the plumber installed it only 10 inches from the floor. In other examples people install them at least 12 inches, or typically 16-20 inches above the floor. He probably just eyeballed it without a tape measure. So when I originally posted the question today, I thought maybe he knew some standard way to make it work when it is low. But now I think, he's just clueless.
 
  #8  
Old 10-31-13, 08:02 PM
F
Member
Thread Starter
Join Date: Oct 2008
Location: US
Posts: 142
Received 0 Votes on 0 Posts
When I break open the wall and raise the height of the drain inlets, I am thinking to keep the existing 2" to 1.5" tee, and putting a new one above it. Could I do that and then put screw-on caps on the existing ones, and use the existing ones as cleanouts?

Otherwise it would be very difficult to cut off the existing tee, because the back and floor of the cabinet would block access to cut the bottom of this tee.
 
  #9  
Old 10-31-13, 08:59 PM
F
Member
Thread Starter
Join Date: Oct 2008
Location: US
Posts: 142
Received 0 Votes on 0 Posts
I am thinking to put a 1.5" sanitary tee or combo wye like this one, above the existing drain stub (and change the existing to a cleanout with screw cap). Would this be ok?


Name:  open wall for drain.jpg
Views: 18463
Size:  25.0 KB
 
  #10  
Old 10-31-13, 09:06 PM
J
Banned. Rule And/Or Policy Violation
Join Date: Apr 2013
Location: USA
Posts: 4,297
Received 0 Votes on 0 Posts
I'll let the plumbers answer that question, but you really need an oscillating saw.
You just made it a lot harder for yourself the way you opened up that wall.
Should have been a nice level and plumb straight sided cut.
Does that hubless connector inside the wall connect to a vent that runs to the roof?
 
  #11  
Old 10-31-13, 09:17 PM
F
Member
Thread Starter
Join Date: Oct 2008
Location: US
Posts: 142
Received 0 Votes on 0 Posts
Yes the rubber connector is adapting the 1.5" ABS pipe to the steel pipe roof vent.

Below that inside the wall is the 1.5" to 2" tee (that it too hard to access to cut out).
 
  #12  
Old 10-31-13, 11:26 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 34 Votes on 26 Posts
Your plumber screwed up, pure and simple. There is no reason that the arm needs to be 2-inch and the glued-up trap assembly is just a problem waiting to happen. If at all possible you need to remove that existing 2-inch sanitary tee and couple up to a 2X1-1/2X1-1/2 inch sanitary tee at the proper level. If you cannot remove the existing tee then cutting the arm off close and gluing on a cap would be the next best, but far from desirable, thing. I suppose you could add a threaded adapter and plug in the cabinet for use as a cleanout but it would not be my first choice.
 
  #13  
Old 11-01-13, 12:12 AM
F
Member
Thread Starter
Join Date: Oct 2008
Location: US
Posts: 142
Received 0 Votes on 0 Posts
You're right Furd, my plumber royally screwed up on the drain height. This is what I ended up doing. This problem came as a surprise, and needed an urgent solution to get the sink working so I tried my best. I could not access to remove the 2" sanitary tee, so I put a 1.5" tee right above it, and turned the plumber's drain into a cleanout.

I still used what everyone here is labeling as a "glued" P-trap (not sure why it has that name). I do not understand what the problem is with this type. For clarification: this P-trap assembly (including its wall piece) is 1.5" not 2" -- it just looks thicker than the usual type. It screws together in two places, after the first down turn from the wall, and where it accepts the sink tailpiece. It is thicker and wider than the super cheap thin plastic adjustable wall piece variety. It still comes apart in two places so the P-trap assembly can be completely removed and cleaned. The only problem I can imagine with this kind of P-trap is that the male threads wear out on the wall side of the assembly (once in 20 years), in which case the wall stub can be cut back and a new thread piece glued on... no?

Name:  newtrap.jpg
Views: 18684
Size:  26.0 KB
 

Last edited by flyingpolarbear; 11-01-13 at 12:49 AM.
  #14  
Old 11-01-13, 05:46 AM
Z
Forum Topic Moderator
Join Date: Sep 2005
Location: USA
Posts: 5,121
Received 84 Votes on 79 Posts
It looks like you did a great job, especially in cramped quarters.

I like slip fittings for the whole p-trap assembly for future options. For example, if you put in a garbage disposal, it would probably require cutting and re-gluing the trap assembly. With a slip fitting, it would just be slipped out and replaced by the new configuration. Not a big deal in my opinion, it looks great.
 
  #15  
Old 11-01-13, 10:19 PM
F
Member
Thread Starter
Join Date: Oct 2008
Location: US
Posts: 142
Received 0 Votes on 0 Posts
I replaced it with a brass P-trap because when there was a lot of water, it sounded a bit too much like a modern new construction home (plastic-y). I had a challenging time with the brass descano compression fitting (the gold thing on the wall) because the wall tailpiece diameter is a tiny hair too small. The brass compression washer would not squeeze down enough. So I took a Teflon washer from an ABS tailpiece fitting, put it into the brass compression assembly, and it fit perfect and works.

Name:  brass trap.jpg
Views: 17230
Size:  33.4 KB
 
  #16  
Old 11-02-13, 07:39 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
Looking good. Thanks for showing us the outcome.
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: