shower p-trap

[rich mills]

Is a p-trap necessary in a shower drain? I have a 25 year old house built on a concrete slab with drain pipes coming up through the slab. I have pulled up my old bath tub and am replacing it with a Swanstone acrylic shower base (the shower base is a retrofit unit so the drain opening in the shower base is in the same place as the old tub drain). There is an 8-10" circular opening in the slab and the 2" drain pipe is placed against the side of that circular opening. There was no p-trap below the tub. Just a "T" on the 2" drain pipe reducing it to 1 1/2". The 1 1/2" "T" connects to a horizontally adjustable drain pipe, which connects to the drain on the tub. I know I need to cut off the T and get back to 2" pipe, but it will be a real bear to add a p-trap in this restricted area, and get the drain back into the correct position to match up with the drain in the shower base. If I need to get a p-trap in there, does anybody have a suggestion how to arrange it?

[Scooter]

Traps are Code here, everywhere, in sinks, baths, showers and floor drains. They keep sewer gas from entering your home. That stuff is nasty smelling, and so I hear, can be dangerous.

Your slab should be no less than 4" thick, with hopefully a layer of gravel and poly below that. With slab on grade, the drain pipes should be no less than about 8" below the finished elevation. That is plenty of space to install a trap, because the offset is only about 4". A "no hub" connector will be the ticket. I would use cast iron.

You may have to excavate a bit deeper and widen the hole a bit larger, but yes, you should install a trap. If you are having dificulty, then retain a licensed plumber. I always pull permits, and you should probably do likewise.

[Bud Cline]

I'm sure everyone here will echo Scooter, a trap is an absolute must.

[John Bridge]

Well yeah, I'll echo Scooter, and I'll echo Bud too, but the trap IS down there.

Rich,

If you dig down in the dirt in the circular hole, you'll find a 2-inch P-trap there. They are installed along with the rest of the subterranian plumbing before the slab is poured.

If your new shower sports a two-inch drain (I think it does), you will have to change the pipe coming up out of the trap to a two-incher. Dig down in the dirt. You'll see what I'm talking about.

[rich mills]

John, you're right again. The p-trap is buried down there. I've trimmed out the old 1 1/2" tub pipe, and I'm ready to bring the 2-incher up to my new shower base.

[Sonnie Layne]

that John is such a know-it-all.

Why doesn't he write a book or somethin'?

[John Bridge]

Sonnie,

Most of my 32 years in the construction business has been devoted to remodeling. I've probably torn out a couple hundred tubs and converted them to showers. Can't get a book out of that, though.

[Sonnie Layne]

Prob'ly right, that's only 6.25 a year. What could possibly be learned with that??? How many cats have you rescued from under the house in that short a-time? How many times have you installed cut-off valves that became inaccessible after closing up the floor? How many times have you laid a curb only to find out the client wanted to use their neighbour's shower door? And I know you've never left a tool under the foundation after closing it off. Pretty boring, I'd bet... think a book is in order. Contributing authors abound.

And isn't it odd... I don't think I've ever poured/placed mud that a cat, if present, didn't autograph the damned job.