On Feb 16, 4:05 pm, Speedy Jim wrote:
wrote:
I ripped out a 30 x 60 tub/shower and am replacing with a 34x 60 walk
in shower (prefab fiberglass pan). The plumbing is currently a 2"
drain that tees into a 1.5" tub drain and 1.5" tub overflow drain. My
plan is to cut off the t and replace with a 1.5" elbow connected to
the shower drain. Will this work and will there be any venting
problems? I.e. is the venting already handled by the existing plumbing
(which is below concrete slab I can't see).

thanks!!

The 1 1/2" P-trap for the tub must be buried in the slab too. Right?

The vent connection (if any) for the trap is downstream
from the trap outlet, so anything you do upstream won't
affect it.

It will probably work just fine, even though 1 1/2"
is considered a bit small for shower drain.

One thing you might consider is placing a TEE where you
make the connection, instead of an EL. In the top of the
TEE, put a cleanout Plug so you can get a snake in.
It may be very difficult to snake thru the trap from
the shower drain opening.

Jim

Great feedback Jim thanks. Maybe you (or someone else) can help
answer this follow up. Why is 1.5" good enough for the drain pipe
when it's a combo tub/shower, but a 2" is required when it's a
dedicated shower? It seems as if a 1.5" is good enough in the first
scenario it should work in the second. Is this just an overly
conservative code issue?