Converting single bathroom sink to double sinks

**maxxfusion** · 03-26-2011, 04:09 PM

I am in the process of remodelling my bathroom. I have a 72" vanitiy with a single sink. I figured since I have the space double sinks would be really nice to have especially with kids. I made this decision late in my remodel project. I looked under the cabinet to check things out and found out that at one time there was double sinks there. So all the copper is in place. Here is my issue. I went to Lowes today and bought some ABS. I can not find the double fixture tee anywhere. I came home and googled the part. I came across the tee at Grainger but its 2 x 1 1/2 x 1 1/2 x 1 1/2. The abs pipe that runs upstairs is 1 1/2.

So my question is does the double fixture tee i need exist in all 1 1/2? I am assuming i will have to order this online.

Any help would be greatly appreciated.

**maxxfusion** · 03-26-2011, 04:12 PM

I just found a double sanitary tee in all 1 1/2. Not sure if I can use that?

**Terry** · 03-26-2011, 04:17 PM

The 1.5 double santee will be a bear to snake. It would need a cleanout on the vent to clear the center.

There are also ways to run it using a wye and two santees that would force the snake downhill instead of over and across to the other lav location.

If I had 1.5" pipe, I wouldn't even bother with a cross, but instead wye off and have opposing santees to to separate trap arms and then revent at 42"

I know that are come countries that will do it, but they must not have ever done service work. I would love to watch them try to get the snake to drop down the vertical.

Just found this picture

**dlarrivee** · 03-26-2011, 05:52 PM

I searched this forum to find this picture from a thread created last year...

**maxxfusion** · 03-26-2011, 05:58 PM

My issue is i dont have the pipes exposed. I would need to rip out drywall to do this.

Can i use this and some 45 degree elbows?

**dlarrivee** · 03-26-2011, 06:03 PM

How would that be any better than the double santee.

Look at what Terry posted, do you a see a double fitting of any type there?

**Terry** · 03-26-2011, 06:03 PM

No.
That type of fitting would need to have vents on each arm. That fitting with a 45 creates an S trap.

**maxxfusion** · 03-26-2011, 06:15 PM

How do they do it in new homes?

**Terry** · 03-26-2011, 06:27 PM

2 x 1.5 x 1.5 1.5 fixture cross.

Double Lav

**maxxfusion** · 03-26-2011, 06:36 PM

So if I could find a 1.5 x 1.5 x 1.5 x 1.5 fixture cross I would be ok? I have looked a bit online and can only find the 2 x 1.5 x 1.5 1.5 fixture cross. Since I had the double sinks at one time and only have 1.5 pipe run to the bathroom can I just use a reducer to go from the 2 pipe to the existing 1.5?

**Terry** · 03-26-2011, 06:49 PM

You can only increase pipe size as you drop down.
You can't decrease.

**maxxfusion** · 03-26-2011, 06:55 PM

I was thinking i could add this to my existing 1.5 pipe from the floor. http://www.grainger.com/Grainger/Pip...ncreaser-1WJE5

Then use a small piece of 2 pipe and connect the 2 x 1.5 x 1.5 1.5 fixture cross.

I cant do this?

**dlarrivee** · 03-26-2011, 07:04 PM

You certainly cannot...

Basic rule of plumbing, you'd be creating a funnel...

**maxxfusion** · 03-26-2011, 07:12 PM

Ok thanks guys. I guess I will be removing some drywall and going off of Terrys pic he posted.

**SacCity** · 03-26-2011, 08:36 PM

So tell me why you can not use two (2) San Tee's facing opposite directions one three inches lower than the other.
It would result in about a 3" difference in heights for the two P-Traps but that should not be an issue, and would have a short section of a wet vent.
Michael