I am redoing a bathroom, gutted to the stud. I am going from a single vanity to a double sink vanity. What is the best why to rough this in. I was thinking two separate drain going to two separate p-traps, which both go to the wall and go into two sanitary tee's that drop down to the sloped waste line. Both tee' will also rise/vent to the horizontal line going back to the vent. Is this right. Don't mind doing the work if I am doing it correctly, just want to know that is correct. Your input would be great.

PS I was also going to tee the supplies and have a total of 4 shut offs, 2 to each sink.

Jjustinia:

I answered your other question.. check that out.

In terms of this question, if the sinks are within 30" center to center of each sink then you can use one ptrap and one vent to pick up both sinks... see picture below. In your case, as posted at the last question you can use an AAV (mechanical vent) to vent both sinks.

If sinks are over 30" center to center then you need to install an individual trap and individual vent to each sink.

Feed each sink with a hot and cold pipe individually.

Check out your other question... let me know if you have questions...

MARK

Jjustinia:

I answered your other question..check that out.

In terms of this question, if the sinks are within 30" center to center of each sink then you can use one ptrap and one vent to pick up both sinks...see picture below. In your case, as posted at the last question you can use an AAV (mechanical vent) to vent both sinks.

Feed each sink with a hot and cold pipe individually.

Check out your other question...let me know if you have questions...

MARK

Thank you!
The drain of the two sinks are over 38 inches apart, it is a 60 inch vanity. There is proper venting on this bathroom for me to tie into. This bath is the downstairs. The other question relates to the upstair bathroom which is directly above. I will look at you other response now. Thank you for your advice

Then you will need to install 2 traps and 1 vent... connecting the vent into other vents thereafter.

Then you will need to install 2 traps and 1 vent....connecting the vent into other vents thereafter.

This is what I was thinking as the vanity has a draws between the sinks and I can cut through. I am not as good with the drawing but those bends are supposed to be p-traps. Anyway, is what I am depicting wrong or an inferior design? I would thinking each having their own vent up from a sanitary tee would be a good thing. And would actually easier for me to install. What do you think?


Meant to say that I can not cut through the draw area.

This is what the rough-in for 2 sinks should look like:

Milo presents the absolute best case if the walls are all opened up... ;) I'm afraid I have confused the two questions you have going a bit Jjustinia!

That is very helpful and seeing make it much easier. That will work well for me. Also on the water supply: are the risers 1/2 in or 3/4. mine are 1/2 should I increase. They are 3/4 just below the floor.

1/2" to each sink is fine!

Milo presents the absolute best case if the walls are all opened up...;) I'm afraid I have confused the two questions you have going a bit Jjustinia!!

Your advice has been very helpful.. my walls are open downstairs and I want to do it the best way.

Your drawing for separate drains and vents for each sink would also work fine, it is actually above and beyond the minimal standards. But I agree with milo that the single drain and vent is the most efficient way to go. Please let us know how things turn out.

that's what I wanted to know thank you. I will go to route milo suggests. Thanks for the advice.


milo,

how thick were the studs in the picture you provided for the rough-in. I have 2X4s and I am having a real tough time squeezing the copper pipes by the PVC with out notching the wood. I am using 2 inch PVC which is what your picture seems to use. I am trying to replicate your set. It looks like you had plenty of room and I am not doing as well. Or are your studs 2X6s?

Thanks!


milo,

how thick were the studs in the picture you provided for the rough-in? I have 2X4s and I am having a real tough time squeezing the copper pipes by the PVC with out notching the wood. I am using 2 inch PVC which is what your picture seems to use. I am trying to replicate your set. It looks like you had plenty of room and I am not doing as well. Or are your studs 2X6s?

Thanks!

I have a very similar setup where I gutted the single Lav and put in a Dbl Lav. I am going to follow your drawing from IRC 3201.6 for using one P-trap. But I don't have the drain pipe off to the side in the vanity where the AAV hooks into like Massplumb's original drawing. To preface: the 1.5" drain pipe does not have a vent on it as the main stack is on the other side of bathroom. So the 1.5" drain pipe right now is just coming out of the 2x4 baseplate about 24" (I left it long to cut later.) So that 1.5" drian pipe is right in line with the lav sink drain pipe. Since there is not the depth for AAV in line with the P trap right behind the sink, how do I put this AAV in?

Can someone tell me how to accomplish putting in the AAV just like massplumb's drawing but the P -trap is in plane with the drain pipe? Unfortunately I can't draw this in plane point of view because, if your looking at the front of the vanity now, the P-trap is inline or in plane with 1.5" waste pipe (which goes to the basement. All I can think of is to make a U on its side after the P-trap and put the AAV on the horizontal U to get me some distance away from the wall.

Thoughts on this problem?
BTW I live in KC, MO with IRC 2006 in my city.