So I am trying to plan the plumbing for the Bathrooms of our home remodel. This is on the main floor and I have a full basement underneath. Also my area uses the 2015 UPC. I think I have most of the drains figured out, but I am unsure of the venting and also have a few drain questions. I will include a few diagrams to show what I am planning but my plumbing knowledge is limited.

Drain Diagram: The tub shower combo is right side drain because I have much easier access to the drain from underneath this way. I could do a left side drain if needed but seems easier to do right since I could tie into the 2" stack close by. Do the stack have a limit on how many different fixtures can run to it?

Vent Diagram: I am not sure on some of this. Can the tub be wet vented off the 2" stack? What is wet venting(I think I have an idea)? For the double sink and toilet 1 vent, I think I can run them up into the attic and then tie into one of the 2 stacks close by.

Am I completely lost here or does someone see a much better way of doing this? I can provide some more diagrams if needed. I appreciate any help.







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extremely difficult without being there and seeing joists layout and what is above the walls.
BUT, lets start with this..
if you can locate a side inlet sanitary tee behind toilet two, you can drain the tub into the small side, the toilet into the large side and continue out the top to pick up the sink. then continue that vent up to the attic.

they also make a double side inlet that if you could fit behind toilet one would accomplish the same thing.
the top of either of those can be reduced to 2 inch . one must stay 3 inch.


of course this is the easiest way to pipe this and may not be possible but given unlimited space this would be simplest.
i don't know what you have for space below but the san tee does not ned to be directly behind the toilet. it can be off to one side and turned at a 45 deg angle to catch the toilet and make it easier to catch the fixture/s draining into the small side opening.

I am adding a couple of diagrams to help show the layout including one that shows the joists for reference. I have a 3" stack and a 2" stack close by as indicated in the diagrams and I would like to keep them in the same spot if possible. I am trying to focus on the drains right now and I uploaded an idea of how I might run the drains. I did not put traps on anything yet but hopefully you get the idea. I believe that toilet 1 would have to go to the 3" drain stack because it cannot reduce in size? I have double sanitary tee on each of the stacks.

you don't want the tub draining into the shower pipe.
every time you let a tub full of water go, it will back up into the shower.
tie the two tubs into the 2 inch thru a double san tee but run the shower into the two inch down lower. the shower will need to be vented separately.

you will need vents behind the sinks. the sink traps can not be higher than their vents.
so, you need a vent stack in the green wall to the left and in the 2x4 wall behind the single wall.

OK I think I am staring to understand but I'm still a little unsure but I will show you what I have come up with. The vent for the double sink will go into the attic and the tie in with probably the 3" vent stack. The other sink in the smaller bathroom will run through the walls and around the corner and connect to the 3" Vent stack. The shower will have a separate vent that tie in to the 2" vent stack? (Not sure about this) I added traps to the showers and tubs. Not sue if the way I have the tub/shower combo plumber is allowed. Looks like a bit of a mess.

WOW, i'm impressed !
couple of minor changes.
the double san tee that picks up the tubs, i would rotate some to make the drains more direct.
the trap for the tub/shower needs to be lowered so the outlet is below the joist. you can not put a 90 like you have. that creates a full "S" trap which is illegal. remember, both sink drains need to be 2 inch all the way. the branch off the san tee in the wall that picks up the sinks can be 1 1/2. this is code for a wet vent/toilet vent.
you asked about a wet vent. well there it is.
the drain for the sink would normally be 1 1/2 but because it is acting as a wet vent for the toilet it must be increased one pipe size. the branch off that 2 inch is not acting as a vent so it can be smaller. CABEESH ?
lastly. put some cleanouts in the piping and remember that because the traps are exposed they must by code have the little cleanout plug in the bottom.
oh yeah, you drawings show tees for toilet wet vent and you do realize they must be "Y"s.

ditto

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

bern, you are agreeing with me for the second time this year.

we will have to wait 'till next year to agree again. hahaha

happy new year.

Ok. Thanks for all the help! I will make the changes and repost it when I am done. I didn’t know I needed y’s at those spots but I will change that to. Some of the routing of the plumbing may have to change as I run into obstacles but I wanted to have a plan of attack beforehand. I am going to try and run as much pipe as I can between the joists so that may change some things as well. The ceiling below is a drop ceiling and we considered finishing it but I think we will keep it as a drop ceiling to have access in the future. Do I only need to add cleanouts on the traps?

running up in the joist space will mean a lot of drilling.
you will need to consult someone smarter than me as to where and how big a hole you can drill.
one of the toilets seems to be going thru a double joist and then 3 others.
if the traps are going to be concealed then they do not need a cleanout in the bottom.
same goes for the rest of the piping. if it is buried up in a ceiling then a cleanout is not required.
the vertical stacks will need cleanouts near the bottom with access panels.
seems like a pain in the neck but if they are ever needed you will be glad they are there.

Ok I made all the changes you suggested on the plans I have. I will have to double check all the joist spacing but I feel like it will look something like this when its all done. I don't think I will be drilling through joists unless necessary. Also I know the 3" stack has a cleanout with access toward the bottom. I will have to check on the 2".

'vent' Y is backwards on the toilet and shower

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

very nice job rotating the double san tee. see how more direct the piping is.


also, on the green wall (i'm sure you know this) that is a double san tee to pick up both sinks.
install it and the other san tee for the single sink at about 19 1/2 inches off the finish floor.
19.5 inches to the center of the inlet/s

I'm sorry I can't help with your question but I was wondering what software you used to make these amazing diagrams? And did you follow any plumbing how-to to generate them. These make your situation and questions so much more clear. Thank you!

I used SketchUp which is free for personal use. Takes a while to learn but I do a fair amount of woodworking and I like to design using Sketchup. The PVC connectors I used I found in the objects library they have on the website.

Thank you! I'll check it out.

So I am having to make some changes in order to minimize drilling through joists. I hope the adjustments are still within code. Reminder I am on 2017 UPC. Basically I changed the way toilet 2 drains and added a vent for the toilet. 2. I also added the double sink drains. The green wall that is against the double sink is exterior wall. Hopefully that wont be an issue. I am allowed to use 1 1/2" for the double sink and toilet 2 vent? I have added some picture below.



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