Options for a misaligned p-trap

[exeunt]

So after having walls plastered, and the bathroom mostly done, we finally bought a vanity and found that now we have a shelf/drawer in place where the P-trap normally resided. Now the outlet is about 2" lower than it should be to support the p-trap in the new configuration.

So, what options do I have here? Ideally I'd like to avoid tearing up the wall. I know I can't introduce a 45/90 turn downwards after the trap as that would constitute an S-trap. What if I introduced a 3-4 inch horizontal run before the downturn to connect with the outlet?

Thanks

 

[Terry]

That wouldn't change anything.

You can cut the shelf below though.
Or cut the wall and raise the tee in the wall.

 

[Sponsor]

 

[hj]

You CANNOT have a downturn of any kind, anywhere in your situation. Use a tubular trap and cut an oval in the shelf for the bottom of it to fit through.

 

[logan]

Not sure if this will work, but you could try a European P trap. I had the same issue and picked up a European P trap at Rona that solved the issue.

 

[Geniescience]

the drawer / wall gap is about 2", I'll assume. If there is a 2" space you could put the P trap against the wall, at the right height. To bring the sink waste to it you would need to install two elbows (bends), one under the sink tailpiece, the other at the only other point that makes sense, above the P trap and aligned horizontally (or a 1/4"lower than) the first elbow. This requires some thinking and some effort. It respects code. To see examples of this same geometry, web search to see what is commonly called an ADA drain. Offset is another good word to use.

To build this you will need skills. In the photo above I think I see a trap arm that is not build the way you will need it. "Trap arm" is the length of pipe that goes horizontally from the P trap to the connection to the DWV where it gets vented by the DWV vent.

The options you have are limited. The one described here gives you an uncut drawer. In the option described here, there is no downturn after the P trap.

 

[Jc60618]

Like HJ said the best thing to do is install a 1.5X1.25 trap adapter with a tubular p trap and then cut the shelf.

 

[exeunt]

You CANNOT have a downturn of any kind, anywhere in your situation. Use a tubular trap and cut an oval in the shelf for the bottom of it to fit through.

A tubular p-trap would be one without a clean-out valve?

The complexity here is that the shelf isn't just a shelf, its the top of a pull-out drawer, making the drawer, or at least part of it useless since anything in line with that trap would hit it whenever the drawer was closed.

I hate to bring it up as an option, as I know that its not ideal, but can I introduce an AAV as part of the downturn to make this "legal" in Ontario, Canada?

Thanks

 

[Geniescience]

HJ is right, but he didn't describe it with the extra clause needed to say "no downturn in the trap arm". It is code-allowed to have a "downturn" in the one manner that I have described it above. If you are unsure what I mean, go do your searching, learning, figuring, and then come back once you get your head wrapped around the concept I explained above. Re-Read my post please. 2/ Search to see similar shapes (ADA lav drain) 3/ Sleep on it. 4/ Post again once you can write honestly that you caught the concept.

 

[exeunt]

HJ is right, but he didn't describe it with the extra clause needed to say "no downturn in the trap arm". It is code-allowed to have a "downturn" in the one manner that I have described it above. If you are unsure what I mean, go do your searching, learning, figuring, and then come back once you get your head wrapped around the concept I explained above. Re-Read my post please. 2/ Search to see similar shapes (ADA lav drain) 3/ Sleep on it. 4/ Post again once you can write honestly that you caught the concept.

Well, I haven't quite slept on it, but I think I understand what you're saying. Researching ADA drain doesn't find me much in terms of imagery, except highlighting shower pans. Offset I think gives me a better idea. Effectively I think what you're saying is that I can install a 90 elbow from the sink to a (near) horizontal run going to where the wall is, where I can attach it to the P trap which may be aligned with the wall. From there I would need another 90 to connect back into the wall. The one part I don't agree with is that it won't require a cut into the drawer, but it may be that the cut is far back enough that it doesn't impact the functionality of the drawer, and may be the best option.

Also, not sure how much skill it would take, seeing as I'm gluing a few elbows and stubs into an otherwise straightforward p-trap. I think most of the skill was in identifying the solution

Did I grossly misinterpret your suggestion such that I need a nap?

 

[Jerome2877]

Two 90's are before the trap one going horizontal then the other changing back to the vertical then down to the trap and into the wall.

 

[Jc60618]

A tubular p-trap would be one without a clean-out valve?

The complexity here is that the shelf isn't just a shelf, its the top of a pull-out drawer, making the drawer, or at least part of it useless since anything in line with that trap would hit it whenever the drawer was closed.

I hate to bring it up as an option, as I know that its not ideal, but can I introduce an AAV as part of the downturn to make this "legal" in Ontario, Canada?

Thanks

If the drawer hits the p trap cut that back portion off.

 

[exeunt]

If the drawer hits the p trap cut that back portion off.

Alright, choice made, shelf cut.

Thanks everyone

 

[Geniescience]

Great, you are competent and decisive. That is a compliment. As you have it now, the P Trap is now at the height required by code. From the P Trap, the pipe will go zig zag to the sink drain tailpiece. It can zig zag with two 1/4 bends or with two 1/8 bends. In the first case, the horizontal segment is, as you wrote it, near horizontal. This meets code. The P trap is as close to the sink as it can be, because something else prevents it from being closer than where you put it. Code says as close as can be. You can have a drawer in the way preventing the P Trap location from being any closer. Code does not say the drawer must be destroyed, mutilated or eliminated. You are allowed to have obstacles which your drain tailpiece extension must go around. Hope this is clear.

 

[Shacko]

HJ is right, but he didn't describe it with the extra clause needed to say "no downturn in the trap arm". It is code-allowed to have a "downturn" in the one manner that I have described it above. If you are unsure what I mean, go do your searching, learning, figuring, and then come back once you get your head wrapped around the concept I explained above. Re-Read my post please. 2/ Search to see similar shapes (ADA lav drain) 3/ Sleep on it. 4/ Post again once you can write honestly that you caught the concept.

I'm sure you are talking about the concept of using the layout of a ADA compliant drain like the inmage I included, over the years I've hooked up thousands.

 

[Redwood]

Now all you need is one of these...
http://www.watts.com/pages/_products_details.asp?pid=2100

Cut the center section and shorten or lengthen as needed.