Can I change the "orientation" of my p-trap?

hpsguy said:

The current bathtub/shower drain is about a foot below the concrete, so I'll have to 90 off of that, to a straight vertical run to another 90 to my p-trap.

Click to expand...

What you are describing here is not legal.

Is there a p-trap currently installed below the floor?

Hpsguy p trap orientation

no [problem whatsoever if you want to rotate the piece as pictured

Yep, that p-trap glues right onto that pipe you have there : "Trap Arm" Digging it down is the right way to do it.


The p-trap is designed to swing to give some flexibility in connecting the trap arm to the tailpiece. You can swing it completely back onto itself if you need to, but offsetting the trap arm vertically is a no-no. :thumbsup:

Thanks for the info, I really appreciate it. Should I just fill the space in with dirt once I have the trap installed?

Another question about the trap now that we have the orientation sorted out, should I use a trap that has a union on it, or just a solvent welded trap? I'm going to put an access panel on the outside wall to be able to access something in case of emergency, but seeing as though it will be backfilled with dirt, will it matter if I go solid or union?

Also, does it matter if I use a 1.5" trap or a 2"?

hpsguy said:

Thanks for the info, I really appreciate it. Should I just fill the space in with dirt once I have the trap installed?

Click to expand...

Backfill with dirt or gravel is what our contractors usually do, some people prefer to cap it with a bit of concrete

hpsguy said:

Another question about the trap now that we have the orientation sorted out, should I use a trap that has a union on it, or just a solvent welded trap? I'm going to put an access panel on the outside wall to be able to access something in case of emergency, but seeing as though it will be backfilled with dirt, will it matter if I go solid or union?

Click to expand...

If it's in the dirt, access is going to be severely limited, so you use a solvent trap. No need for a union on it. We never use those.

hpsguy said:

Also, does it matter if I use a 1.5" trap or a 2"?

Click to expand...

To clarify, are you installing a tub, a shower or a tub/shower combo?

A shower requires a 2" drain. If you are putting in a shower and you only have 1.5" you will not be happy with the way it drains. If you're putting in a tub or a tub/shower, 1.5" piping is fine, BUT : The trap should be the same size as the trap arm. So you put a 2" trap on a 2" trap arm, put a bushing in the inlet, and connect your tub or tub/shower to that. Or if your trap arm is 1.5" then you put a 1.5" trap on it and continue as normal.

But again, a shower needs a 2" drain. The shower drain fittings come 2" standard.

Ill be installing a tub in an alcove then tiling the surrounds and adding a shower head, so I guess a tub/shower combo. The drain line in the picture is a 2" so I'll just use the 2" trap. I picked up one of those bushings that reduces to 1.5" because I noticed that all of the tub drain kits at the store were 1.5".

hpsguy said:

Ill be installing a tub in an alcove then tiling the surrounds and adding a shower head, so I guess a tub/shower combo. The drain line in the picture is a 2" so I'll just use the 2" trap. I picked up one of those bushings that reduces to 1.5" because I noticed that all of the tub drain kits at the store were 1.5".

Click to expand...

That's exactly right then. :thumbsup:

Good luck!