Question on Draining Disposer

[same2you]

I'm about to change the counter/sink/etc in my kitchen and would like to install a disposer. Unfortunately, the sink that was chosen has the smaller sink on the right, and that is where we want the disposer, but the current setup has the drain going into the floor on the right side of the cabinet (then along the ceiling in the basement to the main drainpipe). I've included a diagram of what the currnet layout is (not even knowing if it is code), and was hoping if someone could provide some advice on how to setup the drain with the disposer installed on the right side.



(Red line is the floor)

There's a drop ceiling in the basement, so it is easy enough to move the drain to the left side if needed... but should the P Trap remain in the ceiling below moving forward? Should the entire setup be changed?

Thanks!

[hj]

Most inspectors, and plumbers, would say to change the entire system and put the trap inside the cabinet where it belongs.

[Redwood]

Canada does have some strange code sections that allow the configuration you have...

I guess I like ours better where the trap would be in the cabinet...

[same2you]

So something like below would be the best way to go?

[shacko]

So something like below would be the best way to go?

If you add a vent to it, what you have is an s-trap, a no no.

[same2you]

ok then... it look like the easiest way for me to do this is to stick with our goofy Canadian code, but move it to the left (pictured below)... unless someone has a better idea to retrfit it (note that I will NOT be able to access the wall in behind the cabinet as it is brick (townhouse firewall). Just one more question... how much of a slope should I introduce into the horizontal connection between the disposer and the left sink (in blue)... if any?


Cheers!

[Gary Swart]

Minimum slope for a drain is 1/4" per foot. On a very short distance you don't have to get too precise, but definitely it must slope down.

[jadnashua]

The disposal will act as a pump, and you want a baffel between the two sinks to prevent the disposal from pumping crud up into the other sink. If the sink does not have a vent, then I would move the p-trap to the cabinet and add an AAV off the arm to do the best you can with it.

[Redwood]

If the sink does not have a vent, then I would move the p-trap to the cabinet and add an AAV off the arm to do the best you can with it.

Check to make sure that AAV's or Cheater Vents are allowed by code in your area.

[same2you]

I actually have what I believe is a vent further along the line in the basement ceiling (2nd ABS Pipe ties into the drain at a reverse angle then goes verticle), so couldn't I tap into that as a vent as shown in http://www.terrylove.com/forums/show...ement-rough-in ? So NOW... it would look like this...




And actually.... in looking at this... should I completely remove the vent from its current location in the ABS before connecting it inside the cabinet, or can I leave it connected in both locations? I assume that it shoudl only be connected once (unlike how it's drawn) but hey... I'm the guy that was going to introduce an S Trap earlier on ;o)


(now I can see why plumbers charge so much ;o) )

[Redwood]

You are trying to make a loop vent but the p-trap is in the wrong place,

I was on a Canadian forum just the other day and they said loop vents aren't allowed there..

[same2you]

ughhh....

So is there a solution to this (besides moving to a new house) that would be within the ability of a guy that's handy?

[Redwood]

what you had in post #6 is probably the thing to do

[hj]

Do NOT even try to pipe it like you show in that drawing with the blue lines. There is so much wrong with it, that I wouldn't know where to start, and it would be "impossible" to make THAT system correct. IF they allow "P" traps under the floor, I would thing an AAV would be an improvement.

[same2you]

ok, no worries there. So assuming that I am moving forward with a setup similar to post 6, where would I put the AAV? I've read that it has to be installed higher than the drain, but beyond that I just don't know. Also, if I do install the AAV, should I disconnect the vent that is already connected to the line in the basement?

Sorry for all the questions...