What can I do if drain alignment doesn't allow enough space for p-trap?

Question

I'm remodeling my bathroom. The sink drainage come up from the floor. The alignment between that and the drain coming from the sink doesn't have enough space for a p-trap to be installed so it just falls into place and connects the two (prior to remodel there was no p-trap).

I was thinking having a 45 degree pipe come out of the sink, forward then down, then attach the p-trap, and that would allow enough space for overflow to go back and down to floor drain pipe. My crude image of what I mean, circled in red.

Would this allow for proper drainage?

Tester101 · Accepted Answer

When you purchase a P-trap from the hardware store, you'll end up with these pieces (or something similar).

You'll also want to pick up a 1-1/2 in. PVC 90° slip-joint elbow while you're there.

You'll then want to connect the pieces something like this...

You'll then have to twist the pieces around, until you can get them to fit together. You'll end up with something similar to this.

Though I'm not sure this is code compliant anymore.
In the 2003 version of International Residential Code (IRC), there was this section.

International Residential Code 2003
Chapter 31 Vents
Section P3105 Fixture Vents
P3105.3 Vertical leg for waste fixture drains. A vertical leg (see Figure P3105.3) is permitted within a fixture drain of a waste fixture in accordance with the following criteria:

Minimum trap diameter shall be in accordance with Table P3201.7.
The diameter of Section A shall be equal to the diameter of the trap.
The length of Section A shall not be less than 8 inches (203 mm) and in accordance with Table P3105.1.
The diameter of Section B shall be one pipe size larger than the diameter of Section A.
The length of Section B shall not be more than 36 inches (914 mm).
The diameter of Section C shall be one pipe size larger than the diameter of Section B.
The total length of Section A and Section C shall not exceed the distance allowed in Table P3105.1.
Bends shall be the diameter of the largest connected section.

However, in the 2006 version, this section is gone.

Grunthos · Answer

When the drain goes vertically like this, it is often called an S-trap, since it is shaped like a letter S instead of a letter P.

That center connection in the S-trap is a swivel.  You can do it without the 45-degree section if you rotate the center connection. You can see that in this example:

The more you rotate the center joint, the closer together the input and output are.

Will this be visible to the room, or enclosed in a cabinet?  If it is visible, I can imagine perhaps wanting the aesthetics of a straight symmetrical drain.  If it's hidden inside, just use the S-trap without the 45-degree lead-in.

Russell Hayes · Answer

You're going to have to use an AAV... S-traps have long ago been illegal for the siphon issue that you mentioned.

Marinaio · Answer

My 2 cents:
Mine didn't line up.  I did the following, but check for your local code....

What can I do if drain alignment doesn't allow enough space for p-trap?

4 Answers

International Residential Code 2003

Chapter 31 Vents

Section P3105 Fixture Vents

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