Do I need to vent a walk in shower that is replacing a tub/shower combo?

[m***@gmail.com]

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!!

[Speedy Jim]

Post by m***@gmail.com
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

[m***@gmail.com]

Post by Speedy Jim

Post by m***@gmail.com
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?

[Speedy Jim]

***@gmail.com wrote:

<SNIP>

Post by m***@gmail.com
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?

HaHa! My opinion is it's overly conservative.
Either that or, maybe, 1 1/2" was always too small...

Jim

[Goedjn]

Post by Speedy Jim
<SNIP>

Post by m***@gmail.com
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?

HaHa! My opinion is it's overly conservative.
Either that or, maybe, 1 1/2" was always too small...
Jim

What happens if a standalone shower drains slower than
the showerhead produces water?

What happens in a bathtub?


--Goedjn

[beecrofter]

Post by m***@gmail.com
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!!

Nah it doesn't sound like you are interfering with the existing vent
so don't expect a problem there.

Code however calls for a 2" drain for showers but for the life of me
with all the low flow showerheads in use I doubt you really need more
than 1-1/2

I just built a tiled enclosure on the same sized pan mostly because
the big box couldn't find a set of fiberglass walls that were not
cracked.

[Hal yeah]

replying to mikelikesspam, Hal yeah wrote:
Should you put in a vent for a walk in shower when the rest of the house is
vented?