Really Weird P-Trap Config: Is This A Problem

gotgas

Our plumber installed this P-trap for the drain for the washing machine. Looks pretty strange to me and I am concerned that once water is pumping through it it will not have the capacity to drain fast enough that it will not overflow. I think he did it because we are fairly restricted in our space in this area. What do you all think? We have insulation coming next week and sheet rock the week after so if we are going to change it we need to do it soon.

clammy

Messy primer guy It will suffice being it looks like short turn vent ells glued together most likely not enough room for a solid trap due to poor planning .I do hope that’s 2 inch being code around my parts and the riser should be over 24 if correct. I like he didn’t use primer on the last part also really like that 3 coupling on the stack Oi vey looks like garbage ugh and where is the nail plates not a great sign of one who gives a dam or knowing what to do and do it correctly ,but there’s a lot of that going on these days quite common. Pride and craftsmanship going going gone Just telling the truth not mean spirited Lol
Peace and good luck clammy

gotgas

clammy said:

Messy primer guy It will suffice being it looks like short turn vent ells glued together most likely not enough room for a solid trap due to poor planning .I do hope that’s 2 inch being code around my parts and the riser should be over 24 if correct.

Not sure about all the terminology but the long pipe from the bottom of the drain box to the beginning of the crazy trap is about 19 in.

The two elbows at the bottom are vent 90s. That is what concerns me because I am worried about flow volume.  All of all of it is 2" PVC and it is all glued but he is not a big fan of primer.

He is 79 years old and has been doing it a certain way for a long time. I don't have many complaints about a 79-year-old who comes to work everyday in cowboy boots and puts in a solid 8 hours of plumbing. However, I think he is getting tired by the end of the day and some of this stuff seems a little sketch.

HomerJSmith

Sometimes one is constrained by circumstances. The question is does it work? Does the trap need to be that deep? It might have been better to move that vent around then to increase the distance from the trap 90 to the drain/vent. With a trap that deep, I would not expect the trap to siphon. With the washing machine pumping water so fast would the water backup the riser because of the tight 90's of the trap?
Try it before you buy it (before drywalling it up).

mattmia2

I think it will flow fine but it will be hard to turn with an auger if you ever need to clean it. Probably can find code that prohibits using vent fittings in place of a j bend. Nail plates certainly are required by code too. If a j bend won't fit the gc should have fixed the framing so it would.

Mad Dog_2

He basically "made" a Deep Seal trap which codes generally don't allow unless its on acid & chemical wastes.  Those look like 
"Street Vent elbows" not supposed to be used in those positions.  That being said, I wouldn't get crazy about it.  You'll be able to get a snake 🐍 through those bends.  Mad Dog 🐕 

Mad Dog_2

Leave the Old Timer alone...it's not THAT bad.  Many codes allow 1 1/2" Washing machine  Standpipe and Trap.  He used 2"!  Its done...I've seen so much worse.  Your flow will be fine.  Mad Dog 🐕 

MikeL_2

    While I agree it is less than ideal and a little unsightly, it will work.
   Connecting pvc pipe & fittings is a little more than applying glue. Proper assembly calls for a two step process called solvent welding.
   Charlotte Pipe & Hercules Chemical each have thorough explanations of the required process on their websites.
   Fortunately, most residential dwv systems rarely come under the type of pressure that would cause failure of a glue only joint. We prefer to follow the manufacturer's guidelines ......
   

ethicalpaul

it's no problem, he's been doing it this way for 60 years with no complaints

gotgas

No Old Timer hate here. Nothing but love for the old duffer. He does a great job. He also is charging us $50 an hour, which is ridiculously cheap. We have tried to pay him more but he won't accept it.

I think, just to be sure, we are going to run a garden hose into that drain and run it full of blast to see how it works out. I suspect with the depth of the drain it will be just fine. Also the rough-in plumbing inspection is already done so nobody but me is going to see it. That old Fox is a cagey one.

ChrisJ

Solvent welding PVC is done by chemically lowing the glass transition temperature of the plastic, mushing the pieces together and then allowing the temperature to go back up to normal. The separate pieces literally melt into 1 piece. I've also welded PVC pipe with heat.


Primer pre-softens the pipe and in my opinion, ensures a deeper weld, so to speak.

Even when I used acetone to weld pipe because I ran out of glue, I still softened the plastic several times with it which is similar to what primer does.


In my opinion, primer isn't optional.

gotgas

Mad Dog_2 said:

Leave the Old Timer alone...it's not THAT bad.  Many codes allow 1 1/2" Washing machine  Standpipe and Trap.  He used 2"!  Its done...I've seen so much worse.  Your flow will be fine.  Mad Dog 🐕 

Not that bad...nice! Thanks! He is a good old dude.

No way we would use 1 1/2in  drain on a washing machine. No drain in the whole house is less than a 2 in. A 2 in drain fits fine inside a 2x4 wall. Why would you ever do anything less? 

FYI my opinion is just the opinion of an amateur, so if you like a 1 1/2" drains, don't get all hot and bothered.

ChrisJ

gotgas said:

Mad Dog_2 said:

Leave the Old Timer alone...it's not THAT bad.  Many codes allow 1 1/2" Washing machine  Standpipe and Trap.  He used 2"!  Its done...I've seen so much worse.  Your flow will be fine.  Mad Dog 🐕 

Not that bad...nice! Thanks! He is a good old dude.

No way we would use 1 1/2in  drain on a washing machine. No drain in the whole house is less than a 2 in. A 2 in drain fits fine inside a 2x4 wall. Why would you ever do anything less? 

FYI my opinion is just the opinion of an amateur, so if you like a 1 1/2" drains, don't get all hot and bothered.

Kitchen sinks are 1 1/2" and bathroom sinks are 1 1/4" typically, so I'm not sure how there's no drain under 2" in the entire house?

Reasons to use 1 1/2" on a washing machine? No idea, I'd go 2" assuming there's room.
There's often stuff in walls that could prohibit such things.

gotgas

ChrisJ said:

Kitchen sinks are 1 1/2" and bathroom sinks are 1 1/4" typically, so I'm not sure how there's no drain under 2" in the entire house? Reasons to use 1 1/2" on a washing machine? No idea, I'd go 2" assuming there's room. There's often stuff in walls that could prohibit such things.

With all the hair and the trash and the gunk that goes down the kitchen and bathroom sinks, we run 2in for everything. We have done it on all of the houses we have done.

For the kitchen sink 2 in no problem, the ones we choose fit natively. For the bath sink the biggest we can usually find is one and a half so we use a conversion before we get to the trap. The stand pipe from the sink goes into a 1 1/2 to 2 in and the trap is 2in.

Again, this is the opinion of someone who is strictly an amateur. If you do it otherwise that is fine with me.

ethicalpaul

> Why would you ever do anything less?

A question appropriate for several topics in this thread!

ChrisJ

gotgas said:

ChrisJ said:

gotgas said:

Kitchen sinks are 1 1/2" and bathroom sinks are 1 1/4" typically, so I'm not sure how there's no drain under 2" in the entire house?

Reasons to use 1 1/2" on a washing machine? No idea, I'd go 2" assuming there's room.
There's often stuff in walls that could prohibit such things.

With all the hair and the trash and the gunk that goes down the kitchen and bathroom sinks, we run 2in for everything. We have done it on all of the houses we have done.

For the kitchen sink 2 in no problem, the ones we choose fit natively. For the bath sink the biggest we can usually find is one and a half so we use a conversion before we get to the trap. The stand pipe from the sink goes into a 1 1/2 to 2 in and the trap is 2in.

Again, this is the opinion of someone who is strictly an amateur. If you do it otherwise that is fine with me.

I'm confused.
You keep saying you're an amateur, but then talk like you do plumbing for a business?


"With all the hair and the trash and the gunk that goes down the kitchen and bathroom sinks, we run 2in for everything. We have done it on all of the houses we have done."

HomerJSmith

ethicalpaul says...

it's no problem, he's been doing it this way for 60 years with no complaints

The operative word is "YET".
I put on the bottom of my bills, "All complaints are handled by our office in Budapest." I have never had a complaint.

MikeL_2

  We happen to be helping someone today with a rough-in gone wrong. Here's our WM trap, stand pipe, & vent. A 1.5" trap & standpipe easily handle the discharge from today's watersaving washing machines....

mattmia2

Pipe that is too big isn't good either, too little flow and solids tend to not get carried away.

HomerJSmith

It ain't a soil pipe. Flow is the same regardless of the size of a larger pipe. Movement of solids slow or stop as the liquids run around it.
The photo shows a trap vent to keep the trap from siphoning. Not necessary for a 2" horizontal run that short.

ChrisJ

HomerJSmith said:

It ain't a soil pipe. Flow is the same regardless of the size of a larger pipe. Movement of solids slow or stop as the liquids run around it.
The photo shows a trap vent to keep the trap from siphoning. Not necessary for a 2" horizontal run that short.

Velocity will be higher through smaller pipe and will tend to bring solids with it.

gotgas

ChrisJ said:

I'm confused. You keep saying you're an amateur, but then talk like you do plumbing for a business?

Home builder. New plumber in a new area, hence the question. Also have plumbed several houses myself (4) under the instruction of a master plumber, but definitely a plumbing amateur.

realliveplumber

Thats not a P trap, its an S trap.

The trap arm is too short.

Should have had the carpenter move some studs so it could be done correctly.

gotgas

realliveplumber said:

Thats not a P trap, its an S trap. The trap arm is too short. Should have had the carpenter move some studs so it could be done correctly.

That was my first thought, S-trap. I think we need a 4" trap arm (Edit Thanks realliveplumber!) with 2" pvc?

realliveplumber

You need a 4" long trap arm. The tail piece is 18" minimum - 48" maximum.

HomerJSmith

Chrisj says...

Velocity will be higher through smaller pipe and will tend to bring solids with it.

Au Contraire, mi Capitain, soil pipes operate under their own head. Yes, for piping under pressure. It is the gravitational forces of water that move the solids in horizontal soil pipes.

HomerJSmith

realliveplumber, yes, yes, yes. You have to increase the length of pipe between the trap 90 and the drain/vent.

Alan (California Radiant) Forbes

Thats not a P trap, its an S trap.

Really? S-traps have no vents.



Increasing the size of the drain prevents self-scouring, but I sure like a 2" p-trap on my bathtub.

ChrisJ

Alan (California Radiant) Forbes said:

Thats not a P trap, its an S trap.

Really? S-traps have no vents.

Increasing the size of the drain prevents self-scouring, but I sure like a 2" p-trap on my bathtub.

Drains really fast?

Alan (California Radiant) Forbes

Drains really fast?

I just don't like standing in water when I shower.

mattmia2

I don't think that 1.5" vs 2" is a big difference in velocity and there are definitely good reasons to increase a shower or a washer standpipe or a laundry tub or kitchen sink. If you get too carried away with upsizing things you could end up with problems with clogging.

HomerJSmith

Alan, you're so right. I'm wondering about the minimum length of a trap arm. I know there are maximum lengths based upon the size of the trap arm. I always thought that there had to be a length of straight pipe out of the trap 90 to allow the flow to settle down to allow air in the trap arm to prevent siphoning. hmmm.

realliveplumber

Its 2x the diameter.

realliveplumber

Alan (California Radiant) Forbes said:

Thats not a P trap, its an S trap.

Really? S-traps have no vents.

You're looking at an s strap with a vent in that first picture.

hot_rod

Probably not a legal trap, but it will work. There was some verbiage about the weir of the trap in relation to the outlet into the vertical waste?

Personally I would have used the two 22 bends to off set the vertical waste and used the correct trap. Since the vertical vent runs off plumb by about 2”🤔

I thought code required 18- 30” on stand pipe length?

These are the dimensions I plumber to, per UPC code

ChrisJ

Alan (California Radiant) Forbes said:

Drains really fast?

I just don't like standing in water when I shower.

Mine is plumbed with 1 1/2 copper and I certainly never stand in water while taking a shower.  It's more than fast enough to keep up with 3+gpm

hot_rod

It comes down the the flow rate of the actual machine. It seems line newer machines are flowing faster than some 1-1/2 drains can handle
You can sometimes get that data on new machines

Id worry more  about the horizontal run of 1-1/2 being the limitation. At 1/4” per foot grade maybe 10- 11 gpm?

Mad Dog_2

NYS allows 1 1/2" on  Kitchen Sink Wastes and showers.  NYC are both 2"   The only guys that rough in 1 1/2" in either Area are DIYers or G.C.s, not a Professional.  2" is going to drain a bit faster AND will take much longer to clog.  Oversizing or over-pitching soil (Poo poo ) piping can be a problem, but besides being  a waste of money, oversizing a lavatory, kitchen, or any clear water waste is not going to cause any problems.  Mad Dog 🐕 

Mad Dog_2

The Crown Weir of the trap shall not be above the minimum hydraulic gradient of the vent it is connected to. Otherwise, siphoning of the trap can occur and it essentially becomes an S Trap.  Mad Dog 🐕 

MikeL_2

gotgas said:

Our plumber installed this P-trap for the drain for the washing machine. Looks pretty strange to me and I am concerned that once water is pumping through it it will not have the capacity to drain fast enough that it will not overflow. I think he did it because we are fairly restricted in our space in this area. What do you all think? We have insulation coming next week and sheet rock the week after so if we are going to change it we need to do it soon.

    That framing looks to be 2x4s; drilling for a 2" pipe not allowed where we work.....

ChrisJ

Mad Dog_2 said:

NYS allows 1 1/2" on Kitchen Sink Wastes and showers. NYC are both 2"  The only guys that rough in 1 1/2" in either Area are DIYers or G.C.s, not a Professional. 2" is going to drain a bit faster AND will take much longer to clog. Oversizing or over-pitching soil (Poo poo ) piping can be a problem, but besides being a waste of money, oversizing a lavatory, kitchen, or any clear water waste is not going to cause any problems. Mad Dog 🐕 

 My copper 1 1/2" for the tub was done in the 1940s or 50s.

There's also 1 1/4 which goes to the bathroom sink and then both go into 2" copper.

Judging by the solder joints they weren't diy. Not to mention it's pushing 70 years old if not more and it's fine.