New sink drain trouble

[dstig1]

I'm finally getting around to putting in a laundry sink and cabinet and have run into a snag. The standpipe into the wall is set really low. The plumber set this one much lower than the others for some reason and it didn't become noticeable until I went to install the drain. It is centered decently enough, but I need to make up a good 6-8" drop in a very short distance. See pics below. I have a standard P trap kit with a 6" tailpiece here. If I lower the trap enough to line up with the standpipe (would need a much longer tailpiece) the trap looks like it will hit the cabinet floor and not sit right.

Sure I can grab a couple Street Ells and make the turn and then fit in the Marvel connector for the P trap connection, but I'm not sure how kosher that is. Looking for the "correct" way to do this... Any clues?

 

[ponytug]

If it were me, I would extend the pipe from the sink to the P-trap straight down. The part that you need is called a slip joint extension. For reasons like clogging and flow, I believe that you do not want anything besides a straight pipe from the wall to the P-trap.

I wonder if your plumber thought that you might put in a grease trap. There are code rules around well drain height around here.

All the best,

Peter

 

[dstig1]

The problem with that is the P-trap hits the cabinet floor if I extend the tailpiece down enough. Does not appear there is enough clearance to do it.

 

[dodge man]

Google “low clearance drain trap” and I think you’ll find something that’ll work.

 

[K5lwq]

Sure I can grab a couple Street Ells and make the turn and then fit in the Marvel connector for the P trap connection, but I'm not sure how kosher that is

This is what I would do. What difference does it make if the elbow is in the wall or in the cabinet? It will not hurt anything.

 

[dstig1]

This is what I would do. What difference does it make if the elbow is in the wall or in the cabinet? It will not hurt anything.

That was one thought that crossed my mind, but I wanted to check with The Collective first since I haven't run across this issue before...

 

[Racer4]

Get yourself a couple 1-1/2” sch 40, 90 degree elbows and a short piece of pipe. Put one elbow facing up on the pipe coming out of the wall, then the short piece of pipe with the other elbow into that with the opening facing you. That’s where you’ll put your trap adapter. Play with the height and angle to make it line up with your p trap. Mark everything with a sharpie marker so you can line everything back up again after you glue it. You can shorten the leg of the p trap if you need to.

ETA: you’ll need a street 90 for the top elbow.

 

[LS Tractor Owner]

^^^^^^ This! Very simple, not going to affect the drain flow. Not sure if they make "wide" turn 90's in 1 1/2", but those would be perfect!

 

[MossRoad]

Get yourself a couple 1-1/2” sch 40, 90 degree elbows and a short piece of pipe. Put one elbow facing up on the pipe coming out of the wall, then the short piece of pipe with the other elbow into that with the opening facing you. That’s where you’ll put your trap adapter. Play with the height and angle to make it line up with your p trap. Mark everything with a sharpie marker so you can line everything back up again after you glue it. You can shorten the leg of the p trap if you need to.

ETA: you’ll need a street 90 for the top elbow.

Wouldn't that in essence make an S trap, and that's not code?

 

[MossRoad]

????

Google “low clearance drain trap” and I think you’ll find something that’ll work.

Never knew such a thing existed. I looked them up... Nice!

 

[Racer4]

Wouldn't that in essence make an S trap, and that's not code?

An S trap would be going into a pipe coming up from the floor. And you’re right about that not being code. An S trap, if not vented correctly has the potential to suck the water right out of the trap, allowing sewer gas to enter. The way I described would break the vacuum as the water fell into the larger 1-1/2” sch 40 pipe.

ETA:
I’ve had an S trap in my kitchen sink for almost 25 years with no issues. But it’s teed into a standpipe in the sink cabinet with a pop vent up tight underneath the counter.

 

[ultrarunner]

Maybe it was plumbed with the idea of a washing machine standpipe?

Also… laundry sinks can be much deeper than a regular sink so lower would be better.

Was the plan always for a cabinet?

Lots of different way to approach including a clearance hole if low profile trap not code approved where you are.

I’ve had the opposite problem where the inlet is too high and had to open the wall to lower… deep cast iron kitchen sink with attached garbage disposal…

 

[Racer4]

Maybe it was plumbed with the idea of a washing machine standpipe?

Also… laundry sinks can be much deeper than a regular sink so lower would be better.

Was the plan always for a cabinet?

Lots of different way to approach including a clearance hole if low profile trap not code approved where you are.

I’ve had the opposite problem where the inlet is too high and had to open the wall to lower… deep cast iron kitchen sink with attached garbage disposal…

Very well could have been for a traditional laundry tub sink.

Washing machine would need to be 2” pipe for code, and would have its own trap in the wall or in basement. Definitely wouldn’t stub out that low.

 

[ultrarunner]

A lot of what I run into with existing is 1.5” cast iron with the cast iron trap just above finish floor with 30” length of threaded galvanized for the riser…

I’ve had to choke down washer drain lines to reduce the volume to make it work…

Joys of pre WWII tract homes.

 

[Racer4]

A lot of what I run into with existing is 1.5” cast iron with the cast iron trap just above finish floor with 30” length of threaded galvanized for the riser…

I’ve had to choke down washer drain lines to reduce the volume to make it work…

Joys of pre WWII tract homes.

Ughh. Cast iron sucks. I’m no plumber, but as a GC, I see a lot of crap. The only, and I mean only good thing about cast iron is that it’s quiet. We remove as much cast as we can when doing remodeling. See a lot of lead toilet hubs, tub/shower drains , etc connected to the cast iron. Good scrapping!

 

[ultrarunner]

Cast Iron, Lead Bends, Copper DWV, Galvanized and assorted composites.

Plastic was banned is several local jurisdictions above ground by order of the fire marshal due to toxic smoke generated in a fire…

Another jurisdiction only allowed ground joint 17 ga traps and another required copper for all potable water lines.

Had a building where tenant poured cooking grease down the sink and was told next time she would be charged to clear…

Believed the problem solved but tenant bought drain acid which made Swiss Cheese of the cast iron.

Low Flow lightly used toilets and long cast iron runs is problem I’m seeing more frequently…

Plumbing done well requires a good thought process developed through experience…

 

[Paddy]

dstig,

Ask your plumber why it was set so low? If I did it, I would fix it! That is raise it up

 

[dstig1]

The washing machine has it's own standpipe/box with water supply and the drain in the wall a couple feet over. I have a deep sink in the cabinet now. This was just set too low for some unknown reason. And the plumber wrapped up his work in 2014, so he's long out of the picture at this point...

I basically built this place myself, and this is one of those final details I am getting around to working on 10 yrs later. If you are curious, my house build blog is linked in my sig below. You could be my one lonely visitor this month if you click now!

Need to stop at Menards and get a couple ells tonight... This will not create an S trap, it is just a bend in the drain line. There is still a P trap that will be in place. This was what I figured I would have to do in the first place, but wanted to see if I was missing something before I committed. There has been no sink here for 10 yrs, so a couple more days won't matter...

 

[ponytug]

I'm impressed that there hasn't been odors or leakage...

 

[dstig1]

It was capped by the plumber...It's not open.