I need help with the bathroom plumbing. I replaced the drainage pipe the way it was originally installed, but I figured out it won't pass today's plumbing code. Is the vent pipe through the roof big enough for the bath and toilet? What's the best way to run the bathtub drain? I was thinking about putting a vent right after the long 90 with a wye and a bend up behind the tub into the wall, then tie into the vent to the roof at about 42 inch up above the flood rim of the bathtub. Any help will be appreciated.

Hi Helgramite

All homes must, at a minimum, have one 3" vent stack going through the roof.
If wet venting is allowed in your state, you can use the 2" SINK DRAIN/VENT to wet vent both the toilt and the tub... can save some major money/time if so!

If wet venting isn't allowed then all fixtures must get an individual vent and that gets super tricky.

Where is your sink going in relation to your above picture? Let me know, OK?

Mark

The sink sits on a separate wall outside the bathroom area, the sink drain pipe is ran through the wall into the crawspace then through the foundation wall and I assume is tied into one of the main lines in the yard. The sink drain is not vented unless the old owner used one of those air admittance valves. This is a attached converted garage the house has a couple 3 inch vent pipes through the roof for the other bathroom and kitchen. I know it's a mess

If wet venting is allowed then you should only need to increase tub waste drain/vent to 2" as shown in the picture below...see image.

Run the 2" vent to the attic and connect to a 2" or larger vent or penetrate the roof with the 2" vent by itself. That should do it... ;)

The long sweep 90 is perfect!

Mark

If wet venting is allowed then you should only need to increase tub waste drain/vent to 2" as shown in the picture below...see image.

Run the 2" vent to the attic and connect to a 2" or larger vent or penetrate the roof with the 2" vent by itself. That should do it...;)

The long sweep 90 is perfect!

Mark

Hello massplumber

Will the 2 inch vent from the bath need to maintain a vertical up so high before I connect it to the vent through the roof?

Thanks

In my area wet vents are allowed. Here's how we run our drainage, (see image)


Will the 2 inch vent from the bath need to maintain a vertical up so high before I connect it to the vent through the roof? No! Your vent can be configured any way as long as you maintain slope back to the fixture you're venting and you use a inverted sanitary tee to connect back to a dry vent. Good luck, Tom

You need to rise a minimum of 42" above the finish floor before going horizontal with the vent. After that you can run that pipe just about anywhere and then connect into any 2" or larger vent in the attic as long as you have pitch as Tom mentioned.

You need to rise a minimum of 42" above the finish floor before going horizontal with the vent. After that you can run that pipe just about anywhere and then connect into any 2" or larger vent in the attic as long as you have pitch as Tom mentioned.

Hello mass plumber

I am a bit confused can the vent line from the bathtub drain run horizontal with pitch into the wall, then go vertical up to 42 inch or so, then run horizontal and tie into the toilet vent? See picture.

Lots of thanks

EXACTLY! Install a 2" sanitary tee into the drain line looking straight over to the wall (slight pitch on it). Install a 2" 90 in the wall and look it up and install a 42" piece of pipe. Now use 2 90s to bring you into the stud bay you want to be in and run the pipe up and connect it into the 2" or larger vent upstairs. You can run the pipe horizontal in the attic as long as you pitch it properly!

Thanks for your time and help massplumber and speedball.

All the credit goes to Mark but please keep us informed of your progress. Good luck, Tom

All the credit goes to Mark but please keep us informed of your progress. Good luck, Tom
I talked to inspecter confirmed my county follows UPC.
Since I have to remove the 3 inch main and dig up outside should I put in a clean out? It will be under a deck could probably make a access door.

All plumbing codes require a full-size cleanout be installed within 18-24" of the foundation and brought to grade. This cleanout can be installed outside the foundation or inside at the basement floor.

An access door would be acceptable for most inspectors.

Mark's correct. Our code calls for 18" off the foundation and brought up to grade. However it may be possible to get a variance from the inspector and install your cleanout outside the deck in a assessable location. Good luck, Tom

Mark's correct. Our code calls for 18" off the foundation and brought up to grade. However it may be possible to get a variance from the inspector and install your cleanout outside the deck in a assessable location. Good luck, Tom

Hello again

I got my clean out and tee for my vent in but ran into a problem. I can't fit my 3x3x2 wye between the vent tee and the toilet 90 and maintain a 12" rough in for the toilet. With all the fittings sunk to the hubs I come out to like 13" 1/2 inchs. My question is can I tie into the main vent with a wye right above the tee, and run my shower drain to wye and the vent on through the roof?
see pic

Always so hard to work this stuff over the internet!

You don't need the 2" vent behind the toilet!!!

All you need here is a to have a 3" elbow fitting picking up the toilet and tub/shower and then install a 3"x2" wye into the elbow and if necessary a 3" street elbow to get you to a 12" rough in for the toilet. The toilet/tub wet vent runs to 42" above the floor and out the roof.

That's it! This 2" vent off the tub/shower drain line WET VENTS the toilet and vents the tub.

Your vent needs to run 2" from the tub/shower drain all the way to the vertical 2" vent and out the roof (or connect into 2" or larger drain.

Look at my picture in post #4. All you need to do is what I drew in RED. Ignore your piping in the wall... do what is drawn!

Hope that fixes all this for you!

Mark

Thanks mark

One last question. In your example in post 4 it shows you connecting from the top of the 2" bath drain to the vent. Should I use a wye rolled up there or just a sanitary tee piched upward? Just want to make sure

Thanks again

My diagram actually shows a wye and 45, but I see how it could look like it rolled above the top of the pipe!

Even funnier is that I then answered your question about what fitting to use here (see post#9) and told you to use a sanitary tee fitting! Either way... a wye/45 or a sanitary tee fitting should be fine here. Be clear, however, that each inspector has the final say so you may want to ask... just sayin'... :)

My diagram actually shows a wye and 45, but I see how it could look like it rolled above the top of the pipe!

Even funnier is that I then answered your question about what fitting to use here (see post#9) and told you to use a sanitary tee fitting! Either way...a wye/45 or a sanitary tee fitting should be fine here. Be clear, however, that each inspector has the final say so you may want to ask...just sayin'...:)

OK sounds good thanks for the help.