Would this be considered an S-Trap? The vertical pipe to the right is the washer’s drain and the one on the left goes up a few feet and terminates with an air admittance valve. The whole thing is in the garage (and that wall separates the garage from the house, so not the best fire rated wall)

not really an S just a poor choice of fittings imo

Yeah pass it over unless you need more comment in the report.

Thanks guys! Yeah, I decided to pass it over. That drain pipe isn’t connected to the rest of the house except at the very end before the main line, so I won’t worry about it.

Back in now.
Defiantly call out the lack of a firewall.

Standing trap water in a frozen garage eh? Just looked and see you are in Texas.Never mind the last comment.

(edit here) I just looked up info on traps and perhaps the trap violates what I have below from an older powerpoint.

The vertical between the fixture outlet and the trap weir shall be as short as practical, but in no case shall the tail piece, from any fixture, exceed 24 inches in length

Perhaps someone can explain the reason behind that rule.

A few comments I found Bob on your question;

I think (and I may be wrong) that the reason it limits it to 24" is becasuse if it gets longer, the water from the fixture will have extra momentum on the vertical drop which transfers directly to the trap-seal water. This of course can cause the water in the trap to be “pushed out” or drain (partially) thereby eliminating or reducing the water seal (although some water will probably still remain in the trap).

But the 24" maximum is to reduce odor and the growth of bacteria upstream of the trap. Buildup on the wall of the fixture outlet pipe will breed bacteria and cause odors to develop. 字

I understand the purpose of the maximum length such that a plugged trap would only hold a static head of only so much.

Take your pick. ;):slight_smile:

Bob - That’s for a trap on a fixture. The tailpiece here is a standpipe for a washer drain. That’s usually 18" - 30". :slight_smile:

Sure did thanks! There were many other fire hazards like knob and tube degraded wires in the attic insulation. I also called out as a safety and fire hardware the fact that the dryer was right under the main panel which had openings in it. The entire area around the panel was covered with lent. It was a more interesting house to inspect :slight_smile:

1002.3 Prohibited traps. The following types of traps are prohibited:

  1. Traps that depend on moving parts to maintain the seal.
  2. Bell traps.
  3. Crown-vented traps.
  4. Traps not integral with a fixture and that depend on interior partitions for the seal, except those traps constructed of an approved material that is resistant to corrosion and degradation.
  5. “S” traps.
  6. Drum traps.

Exception: Drum traps used as solids interceptors and drum traps serving chemical waste systems shall not be prohibited.

That fitting is a Y and it should be a T…I would call that an “S” trap in my humble opinion.

A S-trap has the ability to siphon the trap. The trap in the pic does not as it will maintain a seal that is the only concern

The fitting I believe you are refering to is called a “sanitary tee” and is the proper fitting for that application. I have seen it called a “TY” though.

Would you call out a trap in an unheated garage in NY?

Probably not. My garage is unheated and never gets below freezing, but I guess it would depend on the conditions at the inspection.

What ever you call it…Im an Electrician Dude…lol

The fitting where it connects to the vent should not change the direction down again. This is no different in that the gas from the sewer line could come up without the seal present in the trap. Since the connector slops down and not straight in like it would with a T fitting ( short for Sanitary Tee ) I would call this an S trap configuration and so would my municipal inspector…agree or not they would have to change that connector fitting in my opinion.

I wood call it frozen lolol

Who needs traps on Laundry Drains we just dump int the ditch here .

Fig.1: Pans of a DWV system are numbered/reference at left and below, In most installations- you probably will be using 3-In. piping, although the material is manufactured up to 6-in diameters.

Item No. Description
1 Adapter to plastic soil pipe
2 45" Elbow
3 45’ Wye (PxPxP)
4 Fitting and cleanout plug
5 Sanitary tee
6 90° Elbow
7 Closet fitting
8 Sanitary tees (2)
9 P trap with union (PxSJ)
10 Male trap adapter
11 Ptrap,'90` Elbow
12 Coupling
13 Neoprene roof flashing
14 (ABS or PVC) Pipe
15 PVC pipe (2)
16 (*** or PVC) Solvent cement
17 (*** or PVC) Primer

Thanks Marcel…that image shows I am correct…and the image shown by the original poster must be corrected or I will red tag it in my municipal inspection.

**Can you guys tell I am being forced to learn all codes and obtain my CBO certification within a specfic fime period…yeah…yeah…Job Requirements. I guess being an Electrical Expert does not fly anymore when you are overseeing all trades in a local government position…*sigh…oh well

I am forced to learn OBC 2006 along with Energy Code for any new construction if I want to continue to be consulting.

See pages 8 and 9


A sanitary T has a noticeable down slope to help transition from horizontal to vertical flow. A sanitary T is not a straight 90 degree fitting; Marcel’s simple line graphic does not show this.