Moron looking for a simple solution to a major dilemma.

[ilovekittens]

Ya, so I wasn't thinking when I ordered a new kitchen sink to go with new granite counter top that my wife had to have...and wouldn't you know it...the drain is a little to high now (only by like 5 or 6 inches). I've been scratching my head and cursing for days now. Of course the sink is under a window and the drain runs horizontally in the wall. I really don't want to start ripping holes in the wall and would prefer to run a new drain straight down and tie them back together in the crawl space. Is this my best option? Can I T into the old drain for a vent or just cap off the existing drain and install an AAV under the sink. Picture included showing slight height difference. Double sink, no garbage disposal. What would you do? I know- you would of installed a shallower sink. Thanks for having me, hopefully I at least provided someone with a good laugh.

 

[Terry]

Many new homes are going with AAV's now. This one is plumbed to the crawl space.

Kind of looks like they didn't have the dimensions for the sink on this one. I would have offset the drain 8" from center to miss the disposer.
Also the drain from the air-gap shouldn't have a sag in it. I wonder how that's going to work for them?

Someone picked a sink with the drain in the far corner.

 

[Sponsor]

 

[Jadnashua]

The p-trap must be above the floor. Waste doesn't run uphill. You do what you have to to make it work right long-term.

 

[ilovekittens]

Yes, I was thinking a dual p trap may work, but read here that was a no no. Prefer not to release any toxic waste fumes or break any major codes

 

[Cacher_Chick]

More often than not, the drain & vent stack is running up along the side of the window. It would not be too hard to check, and if so, the drain height can be changed in the wall.

 

[ilovekittens]

Agree, I may have to figure out a way to rip out the dishwasher that is blocking my access. It appears to have been installed prior to the countertops because it doesn't just pull right out. The sink and counter tops are already installed which is part of my problem. They look quite lovely.

 

[Terry]

With an outside wall and plumbed the way yours is, that's lowering is normally done before the cabinets are put back in.
If it were my home and you had access in the crawl, I would hit it from the floor of the cabinet into the crawlspace and vent with the AAV.
You may have a lot of drilling now putting it back in the wall.

 

[ilovekittens]

Hence the title, I never considered the drain height when the installers came and put in the countertops and sink. Still have the original cabinets they were never removed. I was able to gain access to the vent stack by removing the dishwasher and cutting another hole in the wall. Now the only thing holding me back is drilling holes in 3 studs it appears I need a right angle drill. A little pricey to buy, hopefully I can rent one

 

[Terry]

You can rent the angle drill.
It might be a good idea to rough out low enough in case someone wants a disposer in the future.
I rough at 16" from the kitchen floor.

 

[ilovekittens]

The waste arm is around 17 1/2 from the floor. I was planning on roughing around 15” was at 22”. I have septic system, garbage disposal probably not the best idea.

 

[ilovekittens]

What kind of slope do I need for the horizontal pipe in the wall that connects to the vent. It’s approx 14” long. Is 1/4 to 3/8 per foot standard regardless if it’s a shorter span

 

[Reach4]

1/4 inch per foot is ideal. 3/8 or even 1/2 inch would be acceptable for performance for such a 14 inch trap arm. In Terry's second picture, the trap arm is only about 4 inches. After you get to the vent, you can go straight down or slope.

The vent is going to be an AAV, right? I am not a plumber.

 

[ilovekittens]

I ended up buying a right angle drill, the rental one was to long. I needed one less than 4 inches and there’s was 7”.

This little Ryobi worked like a charm. Went threw 3 stacked 2 by 4’s. The first 2 x 4 I drilled a 2 1/2 “ hole to accept the sanitary tee and switched to 2 1/8 “ hole saw for the other two.

Probably not perfect but better than what it was. Will check for leaks then patch everything back together. What a pain, I will think twice before I ever change the depth of a sink again

 

[Terry]

You have vent 90's there. You want at least a

medium bend from the wall that will allow snaking in the future.

Nice job though cutting the holes and assembling that.

I like aiming for one side and using a tee like this.

Aiming for the middle works too.

 

[Reach4]

Probably not perfect but better than what it was.

That is a lot longer than 14 inches through the jogs to the sanitary tee. You need a lot more slope control than for a 14 inch path.

Instead of two 90s, you could use two 45s, or even just one 45, between the trap adapter and the santee.

 

[ilovekittens]

Yes can probably go with one medium bend 90 and a 45 . I just duplicated the previous set up, although they did use the medium 90’s

 

[ilovekittens]

Okay it has to be pretty close to perfect now. Swapped out the vent 90 in the wall and eliminated the other.

I do appreciate everyone’s input on this little nightmare of a project.

 

[Terry]

Looking good.
Now you need to get rid of that Red Solo Cup by replacing that shutoff. You can install a compression stop there easily.

 

[ilovekittens]

Ha, that was just a precaution, anytime I touch a turn off they start dripping. I can usually find a sweet spot to get them to stop dripping. I guess the seal deteriorates over time so what good are they?