Interesting drain configuration

[Ralph Schade]

I saw this today and would appreciate some comments. This drain is from a basement bathroom sink with an appropiate trap. I wrote it up as non-standard installation and missing cleanout on the soil stack.

[Jerry Peck]

I don't see the trap, and if the trap is on the other side of where the drain goes into the wall ... then they have effectively created an 'S' trap by going downhill before entering the stack.

[John Kogel]

I call that an "amateur plumbing installation" "There may be hidden problems" as well.
As JP pointed out, the horizontal pipe from the P trap you saw under the sink should go straight to a T in that vertical pipe. This is to allow air to flow back towards the trap.

[Ralph Schade]

Jerry, the sink and trap is on the other side of the wall and I did tell my client that it appears that an "s" trap configuration was created but I wasn't certain. I wanted to confirm that.

[Rod Butler]

If the trap is on the other side of the wall the installation looks fine to me.

[Vern Heiler]

I don't see the trap, and if the trap is on the other side of where the drain goes into the wall ... then they have effectively created an 'S' trap by going downhill before entering the stack.
Call me crazy, but wouldn't "uphill" be a problem? After all, $hit flows downhill!

The roof vent opening could qualify as a clean-out, or a toilet on the floor above.

[Widdershins Saunders]

I saw this today and would appreciate some comments. This drain is from a basement bathroom sink with an appropiate trap. I wrote it up as non-standard installation and missing cleanout on the soil stack.

You're only allowed a single 90 degree change in direction on a trap arm -- I count three 90's and two 22's.

And the trap must not rise above the vent opening.

Also, medium sweep 90's are being used to transition from vertical to horizontal on both the vent and the trap-arm -- These should be long sweeps.

And we have dissimilar plastics joined where the stack exits the slab.

[mathew stouffer]

In other words, she's a beaut clark.

[mathew stouffer]

Ok Im going to ask a question, don't anyone freak out:) I think I already know but Widdershins, can you explain med sweep 90's

[Widdershins Saunders]

Ok Im going to ask a question, don't anyone freak out:) I think I already know but Widdershins, can you explain med sweep 90's

There are three different types of 90 degree sweeps in plastic DWV:

Vent 90's, can only be used above the flood rim because they are not a drainage fitting.

Medium Sweep 90's can only be used as a drainage fitting (in direction of flow) when going from horizontal to vertical

And Long Sweep 90's must be used when going (in direction of flow) from vertical to horizontal.

The upper 90 in this photo is a 1-1/2" Medium Sweep 90.

The lower 90 is a 2" Long Sweep 90.

[Ralph Schade]

Widdershins, dissimilar plastics in your example as well? Solution?

[Widdershins Saunders]

Widdershins, dissimilar plastics in your example as well? Solution?

That's actually 10mil PVC pipe wrap tape in the photo -- All piping penetrations through concrete in King County must be isolated and allowed to move freely.

We generally wrap the pipe three or four times around with foam sill plate seal and then tape it up with either duct tape or 10mil PVC pipe wrap tape.

As for a solution to the OP's photo -- Since transition cements are still disallowed under the UPC, I would have used a CP-33 Shielded Coupling to make the transition from ABS to PVC.

[Widdershins Saunders]

That's actually 10mil PVC pipe wrap tape in the photo -- All piping penetrations through concrete in King County must be isolated and allowed to move freely.

We generally wrap the pipe three or four times around with foam sill plate seal and then tape it up with either duct tape or 10mil PVC pipe wrap tape.

As for a solution to the OP's photo -- Since transition cements are still disallowed under the UPC, I would have used a CP-33 Shielded Coupling to make the transition from ABS to PVC.

Here's a photo of the 10mil PVC pipe wrap.

[Jerry Peck]

There are three different types of 90 degree sweeps in plastic DWV:

Vent 90's, can only be used above the flood rim because they are not a drainage fitting.

Medium Sweep 90's can only be used as a drainage fitting (in direction of flow) when going from horizontal to vertical

And Long Sweep 90's must be used when going (in direction of flow) from vertical to horizontal.

The following are listed in the IRC for changes in direction:
- sixteenth bend
- eight bend
- sixth bend
- quarter bend
- short sweep
- long sweep
- Sanitary tee
- Wye
- Combination wye and eight bend

Reviewing Table 3005.1 (attached below) shows a short sweep can be used vertical to horizontal for 2" or smaller only for fixture drain, 3" or larger that limitation is removed.

[Widdershins Saunders]

UPC 706.2 Horizontal drainage lines, connecting with a vertical stack, shall enter through forty- five (45) degree wye branches, sixty (60) degree wye branches, combination wye and 1/8 bend branches, sanitary tee or sanitary tapped tee branches, or other approved fittings of equivalent sweep. No fitting having more than one (1) inlet at the same level shall be used unless such fitting is constructed so that the discharge from one (1) inlet cannot readily enter any other inlet. Double sanitary tees may be used when the barrel of the fitting is at least two (2) pipe sizes larger than the largest inlet. (pipe sizes recognized for this purpose are 2 in, 2-1/2 in., 3 in., 3-1/2 in., 4 in., 4-1/2 in., 5 in., 6 in., etc.)

UPC 706.3 Horizontal drainage lines connecting with other horizontal drainage lines shall enter through forty-five (45) degree wye branches, combination wye and one-eight (1/8) bend branches, or other approved fittings of equivalent sweep.

UPC 706.4 Vertical drainage lines connection with horizontal drainage lines shall enter through forty-five (45) degree wye branches, combination wye and one-eight (1/8) bend branches, or other approved fittings of equivalent sweep. Sixty (60) degree branches or offsets may be used only when in a true vertical position.

The equivalent sweep of a Wye and one-eight bend would be that of a long sweep 90.

The UPC is far more stringent in its requirements than the IRC, SPC or the IPC.

It has been my experience that most adoptees of the IRC in areas where the UPC is the prevailing Plumbing code pick and choose which chapters to adopt -- Most do not adopt chapters 25 through 42 which cover both Plumbing and Electrical.