Bathroom trap sizes and fitting selection...

[wwhitney]

To the left is the 2" p-trap for the tub. The yellow highlighted pipe would be the lav drain, then the green pipe would be the vent for both the tub and lav. Would this work?

Not as described. Each trap needs a vent at the elevation of the trap. So the green pipe can serve as the tub vent, but not the lav vent.

The lav will need a vent at a san-tee in the wall behind the lav where the lav drain (trap arm) turns downward. And then once the lav is dry vented, it can in turn wet vent the tub in the configuration you've shown. So you could delete the green vent at that point.

How about the WC, how is it vented?

Cheers, Wayne

 

[Reach4]

"Could the yellow be the vent for both and the green be the drain for the lav? "
Yes, but more common would be to vent the lavatory, and then feed the drainage from the lavatory in at the green. That both drains the lav, and wet-vents the tub/shower. That could continue to join the toilet waste and will wet-vent the toilet.

 

[Sponsor]

 

[hhcibtpaun]

Thanks Wayne and Reach4.

So, it sounds like if I run a pipe off of the san-tee that will be on top of the "yellow" pipe, that will vent the lav (and the drain will be below the san-tee. The yellow pipe in the final configuration will be about 3 feet away from the P Trap for the tub. If I could remove the "green" pipe, that would be helpful. However, the distance from the yellow pipe to the stack may be just over 5 feet, so is that OK? Maybe it is, I was thinking 8 feet was the max, but I guess the vent on the lav is only 3 feet away from the tub, then another 5 feet (possibly 6 feet) to get to the 3" stack.

Btw, the toilet is basically directly connected to the 3" stack, so that will be vented with 3" right out of the roof.

Thanks...Mike

 

[wwhitney]

Yes, if the yellow pipe is a lav drain that has been dry vented, then the yellow pipe will be the (wet) vent for the tub. At which point what happens downstream (green pipe, stack, etc) doesn't matter for venting the tub, it's already vented. You can remove the green pipe.

Cheers, Wayne

 

[Reach4]

So, it sounds like if I run a pipe off of the san-tee that will be on top of the "yellow" pipe, that will vent the lav (and the drain will be below the san-tee. The yellow pipe in the final configuration will be about 3 feet away from the P Trap for the tub. If I could remove the "green" pipe, that would be helpful. However, the distance from the yellow pipe to the stack may be just over 5 feet, so is that OK? Maybe it is, I was thinking 8 feet was the max, but I guess the vent on the lav is only 3 feet away from the tub, then another 5 feet (possibly 6 feet) to get to the 3" stack.

The critical distance is from the tub trap U output to the wet-vent point. The distance the lav drainage goes to meet that wet-vent point is not critical. See post #2 of https://terrylove.com/forums/index.php?threads/max-trap-arm-length-for-a-shower-drain-2.4013/

A tub can have a 1.5 inch trap, or it can have a 2 inch trap.

Regarding the toilet, in practice what you say would work, but if it is allowed by IPC would depend on what is entering that pipe above where the toilet enters.

 

[hhcibtpaun]

Regarding the toilet, in practice what you say would work, but if it is allowed by IPC would depend on what is entering that pipe above where the toilet enters.

Thanks.

This is what I am using for the toilet. The vent will be out the top, and the tub/lav drain will feed into the side. and the toilet will come in from the left/front....I assume this is acceptable?

Thanks...Mike

 

[wwhitney]

That's definitely fine if the top is a dry vent, i.e. nothing is draining in from above.

It's worth confirming that the 2" side entry has the same radius that a 2" san-tee has, rather than a sharp 90 interior corner. The latter would not be allowed.

Cheers, Wayne

 

[hhcibtpaun]

That's definitely fine if the top is a dry vent, i.e. nothing is draining in from above.

It's worth confirming that the 2" side entry has the same radius that a 2" san-tee has, rather than a sharp 90 interior corner. The latter would not be allowed.

Cheers, Wayne

Thanks. Yes nothing else draining from above. This is the description of that fitting from Home Depot:

3 in. x 3 in. x 3 in. x 2 in. DWV PVC Sanitary Tee with Right Inlet. I will verify, but I am 90% certain it is radiused...

Thanks...Mike

 

[hhcibtpaun]

OK, I have a solution and thank you Wayne and Reach4.

One more tweak. This is originally what I was thinking, but was not sure it would work, but I will ask just in case. If I used the green as my run, would that work (basically the main run is just in a wider joist bay and the LAV would be offset one bay. I was thinking this may not work since it is not one "smooth" run. I can mock something up if this is confusing.

Thanks...Mike

 

[wwhitney]

If the green line represents piping in a single horizontal plane (well, with 1/4" per foot slope), and the bottom circle is the dry vented lav drain coming down, and you use a combo where the lav drain joins the tub drain, that's fine for having the lav wet vent the tub.

Cheers, Wayne

 

[hhcibtpaun]

If the green line represents piping in a single horizontal plane (well, with 1/4" per foot slope), and the bottom circle is the dry vented lav drain coming down, and you use a combo where the lav drain joins the tub drain, that's fine for having the lav wet vent the tub.

Cheers, Wayne

Nice. I think that is what I was trying to portray. I will do a final mockup before I start to drill and glue, to make sure all is well.

Thanks....Mike

 

[hhcibtpaun]

I will do a final mockup before I start to drill and glue, to make sure all is well.

Here is what I plan to implement. I assume I am good ?

Left is P-Trap for tub, center is Lav drain and vent, right side will continue to main stack. The lengths are not the exact length, just what I had lying around to mock up.

Also, is there a preferred drain height for the LAV. In my head I was just going to put it like 18" above the floor. I have been measuring the various drains in my house as a gauge.

Thanks....Mike

 

[hhcibtpaun]

Hopefully, my final question on my Drain/Vent project.

So, I started in the basement with a 2" vent, that vents the Washer and Utility sink. That runs up through the wall into the kitchen. In the kitchen I will run a 2" vent into an upside down WYE to join to the vent from the basement. This will then go to the second floor and pop through the closet floor which shares a wall with the bathroom. In that bathroom I will have a 2" vent that will be used to vent the bathtub and lav. Again, the plan was to join with the 2" vent in the closet (either upside down WYE or San-Tee). This single 2" pipe will then go into the attic and ultimately through the roof.

So, can the 2" pipe, that will eventually poke through the roof vent the washer, utility sink, kitchen sink, lav and bathtub? I think it all adds up to 12.5 fixture units...so I think I am good? At one point I contemplated upsizing the vent to 3" when I hit the attic, but not sure the extra diameter for 10 feet or so at the end would matter.

I have to find a person to get the vent through the roof and it is a slate roof...so if I have trouble or long waits, I will stick an AAV on in the attic as a temporary measure unit I can get the vent sorted out "properly".

Any comments appreciated.

Thanks...Mike

 

[Reach4]

The extra diameter up top is to prevent freezing closed.

 

[Jeff H Young]

18 inches is a somewhat standard guess at putting santees for lavs , sometimes its a bit low but if we have unknowns and want to get it done 18 is likely what Ive guessed at. I actually prefer higher though and if you go with some of the cabinets that have a shelf on the bottom it sucks being low and notching out the shelf

 

[hhcibtpaun]

The extra diameter up top is to prevent freezing closed.

Thanks, that makes sense.

Jeff,
Thanks for the lav height response.

Mike

 

[hhcibtpaun]

Apparently, I have a new question every few days. Today I was carving out my studs to run the Kitchen Sink vent. The drain is under a window, so I am limited by the window on what I can do with the vent. This is the approach I was going to go with:

If I do this the CL of the drain is somewhere around 13 or 14 inches above the floor. So it will probably end up like 9" or so above the bottom of the cabinet. Not sure if that is too low. I looked around the site and seems like anything can go (within reason). I was shooting for 16", but I can live with 13" or 14" unless it is problematic from a code perspective.

Here is another option, but I am not sure this is allowed:

Can the above approach work, or is the horizontal run below the water line a no-no?

Thanks....Mike

 

[Jeff H Young]

They want it to remain vertical until 6 inches above flood rim so it looks like the 45 immediately above santee. Depending on sink depth and if garbage disposal and 2 compartment sink. 13 or 14 not that low it is at about as low as I go. You can put the street 45 into bottom of santee Probably entail replacing the cripple and moving over a bit to right off layout no big deal

 

[hhcibtpaun]

Thanks Jeff.

 

[hhcibtpaun]

Folks,

Been a few weeks. I finally was able to get a start on my bathroom plumbing. Was driving myself crazy with getting the pitch on a 10" length of PVC. I did a search for tips on how to make that happen, and I think I saw here, that maybe for that length horizontal might be ok (and maybe fittings have pitch built in. I was about to abandon this part of my project and call in a plumber....then I figured I would give it one more go. So, this is what I have:

The blue line in the picture on the right is just under 10" in length and is the drain from the lav. If that is OK to be horizontal (it connects a 90 long bend from the lav to a horizontal combo to connect into tub drain).

In the picture on the left I think I have to redo all of that since I glued sections to make my life easier, but when I went for final assembly, everything was slightly off from an indexing perspective. So, this means I will have to buy a new tub drain. I am using a 1/2 T-Waste kit. Is there a way to just buy the PVC pieces? I don't need the drain, since I have multiple. Also, is there any preference toward a 1 or 2 hole plate? Pop-up or twist drain?

Also, using a 2" trap off the tub brings the trap just under the joist. I may be able to live with this since I have to pad my ceiling down a bit. I assume it is better from a clogging perspective to use a 2" trap?

so, do I need to lose sleep over a horizontal 10" run?

TIA...Mike