We don't have a copy of the UPC, but we do have the code check plumbing which does have a little bit of it in it.

We're starting off with the Master Bathroom, and I've sketched up what we have in mind for this bathroom setup.
What we're not sure of is how to do the venting right, especially with the tub.

Diagram A is what we're hoping for, but depending on the location of the joists, diagram B might be what we end up is. Would vent locations work in these diagrams?

Do we need more clean-outs for this bath configuration?

I've updated my drawing yet again. My numbers are from the UPC 2006 (I think).
I honestly don't know if this is right, so please someone take a look and let me know if that will work, and if my drain and vents are right, the size is right, and my fittings are right.
Also, where do the cleanouts need to go?

You have S or L in four places. I guess that is a question. In the two places where the outlet is horizontal, you'll need a Long sweep, just as you have already indicated under the WC.

The horizontal par of the vent needs a slope too, even through the bends to the tub, higher at the center point, lowest at the turn down to the tub.

I don't know the minimum number of cleanouts you will be required by AHJ.
Since you're doing all this yourself, why not have more cleanouts?

Everything will be sloped at a 1/4" per foot for the drains. Is that good enough for the vents too? If so, what you are saying is that the location of the double T on the center vent pipe that the lavatories and tub vents connect to will be dictated by the slope of the tub vent, since that will be the longest run connecting to it. Is that right?

We are not required any inspections, so the AHJ will not be seeing what we're doing. My area is under UPC, so I definitely want clean-outs where they should go. And even if I wanted more than required, my question is where do they go?

Does the clean-out have to face up? Or can it be sideways or even facing down (though I'd hate to be under one when cleaning!) depending on the location and the available room to get to it. Is there a minimum amount of space that I need to reach a clean-out?

Since you say that each drawing is better than the previous one, does that mean that I'm on the right track? My pipe sizes seem to be right and this bathroom should be ok? Or do I still have more work to do? Thanks!

Thanks!

Yes to all your other questions.

In your last drawing, the aerial view in the left corner shows the WC connecting with a tight bend instead of a combo or two 1/8ths. No big deal, just pointing out the drawing doesn't show the large radius of a combo.

We don't have an exact number on the distance for the drains. But if they need to be a certain distance, I'm sure we can accommodate it. The center to center distance in the plans shows about 5' between lavatories. The distance between the walls on either side is about 9'-1 1/2". The framing is done, but we haven't measured to see if the real dimensions match up with the plans.

Here's a picture that shows the dimensions of that bathroom if that will help anything.

Thanks Davidro1 for the reply. I'm doing the diagrams in the very basic software Paint, so that's why everything looks like a 90º corner. I just wanted to show the path we would be following, and labeled the fittings to show what we'd be using at that location.

I really appreciate the help. Thanks

Beginning with the W.C.. Note that you show the vent in the partition wall adjacent to the W.C. location. That is fine, however a W.C. is the exception that proves the rule. The purpose of putting the vent close to the fixture is to insure the trap will not be sucked dry, however in the case of a W.C. we actually want the sucking action to aid the flush so if you place the vent a little further away the W.C. will actually flush better. Under the UPC we may place the vent up to 8‘ from the W.C. (Under the IRC if a W.C. is the only fixture on the line we may run the line an indefinite distance from trap to vent).

The next critical dimension is the tub drain in the upper right corner. Notice that we will be WET VENTING the tub to the vent riser by the lavatories. Normally a tub requires a 2" drain line, but under the UPC if we wet vent we must increase the line by one nominal trade size, therefore we will install a 2" drain opening and trap on the tub, but waste arm from the trap to the vented branch line is 3" , and the vented branch line is also 3" to the base of the vent riser by the lavatories. Understanding that we may not decrease the size of a line in the direction of flow, it then stands that the vented branch line must be 3" from the base of the vent down to the main drain.

From the vented branch line we must install a 2" riser up to the level where the lavatory drain line will run horizontal behind the lavatories. The reason is because each lavatory is rated at 1dfu and the line is serving two lavatories for a combined load of 2dfu. Under the UPC an 1-½ line is limited to 1dfu therefore we make it 2" which is rated for up to 8dfu‘s max in a horizontal plane or 16dfu vertical.

The lavatory waste arm on the left side is connected to the horizontal drain by a 1/4bend (90 deg sanitary elbow). On the right hand side of the ¼ bend you will install a Wye and attach a vertical vent line. The line must run up until it reaches an elevation at least 6" higher than the finished flood level rim of the lavatory bowl, then it can turn horizontal and tie back into the vent riser. From the Tee where the lavatory drain connects to the vent riser and up to the roof, the vent may be 1-½." The re-vent line from the lavatory on the left back to the vent riser may also be 1-½"

You will need a cleanout on the upstream end of the main drain and another one at the base of the vent riser by the lavatories.
.

I notice that no mention was made regarding what was described as "a number of mistakes". No time spent on helping understanding.

Only a plumber on site can say whether this minimal elegant drawing fits the physical situation. Overall, my feeling is that the drawing is elegant, and impressive, but it might not be helpful for learning and it might not fit.

-david

The distance of the wet vent on the tub is more than 6'. So I moved that over closer to the tub to make the 6' work. Also to fit within the joist cavity. I now have both the main floor framing and the basement framing on the drawing as well as the location of the joists. So hopefully that will help a bit to figure out how to make this fit.

The other problem is the main drain. It runs perpendicular to the joists, and to keep that at the same elevation we'd have to drill through every joist. We have to stay at least 2 ft away from the load bearing wall per our joist mfg. instructions, so we can't drill at that location. The main drain has to run below the joists.
If I didn't mention this before, this is over a finished basement, and the location of main drain line is restricted to a closet below to minimize bulkheads.

I think this also might make the length of the toilet wet vent longer than 8ft.

So here is my revision, but what I'm not sure now is if the toilet vent would work with dropping the main drain line to run below the joists.

Also, the other problem we noticed was that even though we asked the framer to locate the joists so they would not interfere with the toilet plumbing, he didn't do that. So that joists is right under where the water closet drain needs to go.
After discussing options, we decided it would be easier to redo the framing and get rid of a wall, and create a built in book shelf in the bedroom side to slide the W.C. forward so that the drain is now within the joist cavity. Rather then cut the joists to created a boxout for the drain.
The other joist problem is the under the tub. Seems like the framer tried to accommodate the tub drain by shifting the joist, but we think he shifted it to the wrong side.
We now have to go get the dimensions of the tub we want and see where that drain will end up in relation to that joist.

Lazypup, will the toilet vent still work if we do it this way? Also, you explained that to wet vent a fixture, you have to increase the drain size as you explained for the tub. Is the toilet considered wet vented? If so, why is the drain still 3"? If not, why isn't it considered wet vented?

And as David mentioned, I wouldn't mind if you pointed out what my mistakes were in my previous drawing so I can learn to avoid them when I work on the next bath.

Thanks,

Boontucky

last Tuesday you posted three times. I'll try to help here. 1st post: no to question #1 because you are asking if you can make the WC drain arm go south (downhill) before venting; the answer is no, so either go back to something like the way it was in your first series of diagrams, with the venting closer to the WC like for example angle the WC drain to hit the wall at the two-wall corner if you can put the vent there, or position the WC elbow down lower, e.g. under the subfloor (but, finished basement underneath). The other questions about wet venting might have no clear answer because defining wet venting is often fuzzy, in my opinion. Some will tell you not to upsize any of the drains for wet venting a few feet. Upsizing is critical when you have a distance that corresponds to a certain physical maximum related to the pipe *and its slope*. I've seen more bathroom sinks with the smaller size 1.25" drain to start with, than with 1.5", and so following this logic, a 1'5" drain is plenty big enough for two sinks. I've seen tubs wet vented with 1.5" drains, not 2". Certainly not 2.5" (or bigger). Even in large concrete condo buildings that have to meet stricter codes (commercial / industrial), stricter than residential (e.g. wood frame) house codes. So, you might be able to safely disregard all the finer points of wet venting and upsizing. Check with a Master plumber in your town. They all will talk when asked to talk. They cannot refuse to answer. This is in their professional code of conduct.
-- in your 2nd post, you asked about the cleanout. Put a change of angle wherever it makes sense with respect to your physical barriers, and then you have the option of a cleanout there at that change of angle. Using two 1/8th bends instead of one long sweep gives you a slightly different place to place a cleanout. Hope this helps.
-- in your 3rd post you asked again about venting the toilet. Answer: Did something make you think you could not vent it farther uphill, closer to it? Lazypup said it is fine.

In your diagrams you didn't draw the Wyes at intersections, and this is serious, but I think you wrote somewhere that you cannot draw Wye's (lazypup has Wyes in all the right places). You need to say each time you post a diagram that you will put a Wye at these connections. This may be the only error or mistake.

About joists: for a WC, see offset flanges. For a tub, see "tub shoe" and you can send the drain to any offset position prior to it going down into the P trap. The tub drain and overflow get connected together and then that combined pipe goes down towards the P trap which can be anywhere in the horizontal plane of its outlet pipe (not higher) -- although the word anywher is too strong, you get the picture. No big deal. Most ideal is if the P trap is located directly underneath the overflow or directly underneath the tub drain hole, but don't become a perfectionist, just build a working system. Not to worry, not a big deal to offset it. Search on "offset" as a key word, like the "offset tubular" thin walled pipes under bathroom sinks that zigzag twice 135 degrees around an obstacle.

- - Hope this is clear.

I looked at the offset flanges. The problem is that the joist is right smack at the center of where the W.C. drain has to go, so even the offset flange won't fit.
We haven't finalized the tub decision yet, and some of the models we're looking into have the drain in the center, so we might be ok there. But thanks for the offset tip on the tub.

I'll mess with the W.C. vent again. I had an inkling that it wouldn't work that way. So thanks for clarifying that out. If Lazypup doesn't answer my request to point out what my mistakes were in the original drawings, I'll have to go with my last venting option I had before. I figure they make that special low heel elbow for a reason. I did like Lazypup's version better because it would be easier to run the drain between the joists, then having to work perpendicular through the joists to fit in what I had in mind.

I really appreciate your time looking into this. The last plumber we talked to wasn't very interested in "helping" me understand things when he did the plumbing under the slab. So I'm hesitant to bug a plumber when he's not going to get paid for his advice. That's why I'm on these forums looking for help.

I'll post back an update, and I'm sure I'll be around bugging for more help since I do have more plumbing to figure out.

Oh, and I thought I drew the diagram right. I'm assuming you're talking about the plan view with the red lines. I figured since the Wye's are vertical, you don't draw them in. And the 3d diagram in black shows wye's at those locations, or at least I thought it did.
How should I have drawn those Wye's?

Thanks.

I could have mentioned yesterday that venting more than the minimum is also good, so your "overvented" diagram Nov 25th is good in that respect.

Without being a Master plumber, I'll offer my view of what you might consider as a way to handle the cleanout you are having a hard time with (the one under the sinks, i think) : just route the drain wherever it will make sense for you to put a cleanout into the line, at a change of angle. You are not required to stick to vertical lines.

F.y.i. , and a.f.a.i.k., a tub with a drain in the center is harder to install. No big deal, just good to know, that it will take more time, effort, attention, skill, tools, etc.

hth