I am planning a new bathroom on slab in lower level of house. It will include 1 shower, 1 lavotory, and 1 toilet.
shower has its own drain 1.5" drain from previous lavatory. I will add a trap and vent. I would like to connect the toilet and lavatory to the same vent and drain. The toilet has 3" drain that will do a 90 after the 4" x 3" closet bend. After the 90, I would like to have a 3" x 3" x 1.5" sanitary tee. The lavatory would drain here and also extend vertically for the vent. Does this seem acceptaple? Any help would be appreciated.

Your toilet can not be upstream of the sink. Can you tryn this around a bit, the piping not the room lay out and put the sink first on the branch and then the toilet?

Hi Buildz...


Check to see if WET VENTING is allowed in your area... if so, you can save labor and material and wet vent the shower and toilet using a 2" lavatory drain and 2" lavatory vent... see top diagram below.

The wye fitting that comes off the toilet drain must roll above the centerline of the drain pipe to act as a vent... see bottom diagram.

Find out if wet venting is allowed in your area and then we can discuss more, OK?

Mark


I saw your post in the comment box.. please post answer to the box at the very bottom of the page... ;)

PS: A shower drain requires a 2" drain.

Waiting for info. About wet venting in your area...

Thanks.

Mark

Thanks. The pictures were helpful. I will check with the building department to see if wet venting is allowed.

I guess I should explain that this is not a completely new bathroom. Instead, I am adding the shower and moving the toilet and lavatory. Please reference drawing.
I did check the local code which is the Ohio plumbing code. It reads:

"Any combination of fixtures within two bathroom groups located on the same floor level is permitted to be vented by a horizontal wet vent. The wet vent shall be considered the vent for the fixtures and shall extend from the connection of the dry vent along the direction of the flow in the drain pipe to the most downstream fixture drain connection to the horizontal branch drain. Only the fixtures within the bathroom groups shall connect to the wet-vented horizontal branch drain. Any additional fixtures shall discharge downstream of the horizontal wet vent. The dry-vent connection to the wet vent shall be an individual vent or common vent to the lavatory, bidet, shower or bathtub. In vertical wet-vent systems, the most upstream fixture drain connection shall be a dry-vented fixture drain connection. In horizontal wet-vent
systems, not more than one wet-vented fixture drain shall discharge upstream of the dry-vented fixture drain connection."

I also read that the shower needs a minimum trap size of 1.5" That was my reasoning for using the existing lavatory drain and just adding a trap and vent. I was just going to reduce the shower drain from the 2" opening to 1.5" at the drain and into the 1.5" trap. Shower floor to trap is about 12" vertical. Does this sound OK?

Back to the drawing. The red is the existing drain line and the blue is what I would like to do. The green dotted line is where the old wall was.
Thanks also for the info on posting. Sorry about that.
Also - I can not figure out how to attach my drawing. Thanks for your patience as I am new to all of this

Here is the link for the bathroom drawing. Sorry about the delay.
http://img820.imageshack.us/i/bathroom.pdf/

Hi Buildz...

Someone from the site combined my last post to the older post... just so you know.

I'll review everything and post back on this later tonight or first thing in the early AM.

Chat soon...

http://img820.imageshack.us/img820/4204/bathroom.pdf

Hi,
Yes, wet venting is permitted on all 3 fixtures. You have to make sure that there is a minimum 2" vent that's serving all three at once.
Starting in the uppermost drain, the lav has to be 2" wet vented section, then shower drain has to be increased to 3" to serve as drain for the shower and wet vent for the water closet. If vent is not increase to 3" between shower drain and water closet wet vent, you will not have equal atmospheric pressure to assure good flow air through the vent and draining.

Also, wet venting permits four 1 to 2 fixture unit fixtures not counting the water closet being the 5th fixture. And cannot be more than 6' apart and it has to be on the same floor.

It is a lot of information but it is the universal plumbing code. Good luck!

Argaiu... never heard of codes like that before? Buildz presents that he only needs 1.5" trap for a shower in his area whereas most codes require a 2" drain.

In terms of wet venting a bathroom group, most codes call for a 2" wet vent so this "increase to 3" between shower drain and water closet wet vent, you will not have equal atmospheric pressure to assure good flow air thru the vent and draining" that you mention is news to us... ;)

So much for the "universal code"... huh?

BUILDZ, codes differ from state to state, but they usually follow a basic set of standards. It seems your state has codes that are totally different from any I have been presented with previously (almost 3 years online here). Argaiu seems to present another exception to the national rules...

At this point, as presented in your drawing, I'm thinking you'll want to add an individual 1.5" vent for the existing 1.5" shower drain and then pipe up the toilet with a wye fitting to pick up the lavatory drain and vent. I'll look this over a bit more when I pop in from work tonight, but if this is being inspected by a plumbing inspector in your area I'd set up an appointment and go in to discuss this with him so there are no mistakes or need to repipe anything.

Thanks guys...

Mark

Thanks for the help Mark. I have been trying to contact the plumbing inspectors in my area, but have received no call back. Maybe they are really busy. I will keep trying. I would like to especially check with them about the 2" trap for the shower, as this seems out of the ordinary to you and others. If anyone is interested, here are the locations for what I read on shower requirements in the Ohio plumbing code.

Chapter 4 - Fixtures‚ Faucets and Fixture Fittings

Chapter 7 - Sanitary Drainage