Wash Machine drain

[JCM5]

Why is there a max height for the standpipe 0f 42"?
Longer better

Also for the 2" trap can it be placed in the basement?
Ease of cleaning

Overflow pipe down to basement just in case?
So the first floor doesnt flood, dump into workroom better

Any thoughts?

[The Builder]

If the trap is located outside the wall it must be accessable in the same room. Also in addition it is good to get the building codes from your LOCAL inspector for the projects, that way it won't be guess work when your doing a number of projects

[JCM5]

Ok soo its sounds like more of a code violation then functionality point.

Lets ask this another way.

No trap at all,
Sealed point for washer drain into 2" Y pipe. Other side of Y connected to a cheater air valve. This would not allow sewer gas in the house. The gas would be trapped by the valve and the washer disharge pump.

No trap to clean

I know, check local codes.

[LazyPup]

"If the trap is located outside the wall it must be accessable in the same room"

That is not necessarily true

If you are under the Uniform Plumbing Code (UPC) the trap is required to be in the same room and a minimum of 6" but not more than 18" above the floor. The top of the standpipe is then required to be a minimum of 18" above the water level of the trap but not more than 30" above the water level.

The standpipe, trap & drain line are required to be 2" diameter.

Under the UPC the maximum allowable total developed length of a 2" fixture arm measured from from the trap weir to the vent opening may not exceed 5'

Under the International Residential Code (IRC) the trap may be below the floor.

The top of the standpipe must be a minimum of 18" above the water level of the trap but not more than 42" above the water level of the trap.

The standpipe, trap & drain line must be a minimum of 2" diameter but not more than 3" diameter.

The total developed length of a 2" fixture arm may not exceed 8' from the trap weir to the vent opening.


Under both codes the proposed overflow pipe in your drawing would be code prohibited.

The reason for limiting the length of the standpipe is to control the velocity of flow through the trap. If the vertical line is too long the velocity of flow through the trap is too great and it results in a siphoning action that would suck the trap seal water out, leaving the trap dry and allowing sewer gasses to enter the structure.

In the original post you mentioned that you are limited to 42" on the input so I am assuming you are under the IRC.

I am attaching an illustration of the IRC code requirements

[The Builder]

For most installations thats how it go's thats why I said check with the LOCAL inspector. Location is EVERYTHING and is over the national code. But that was great information you put there to help them out.

[JCM5]

I did pull the local codes and found what you mentioned.

Heres the problem I am having with the standpipe/trap opposed to the current dump into the laundry tub.

With the current Laundry tub design, you can visually see and change the lint filters on the washer outlet.

You can see the soap bubbles in the tub.

The homeowner wants some sort of overflow on this trap. The plan is to remove the Laudry tub and put in cabinets in this area along with new undercounter washer and dryer. The homeowner wants some assurance that the washer disharge will not come out of the stand pipe (attach it with clamps etc) and when the trap overflows for what ever reason the water doesnt come out of the stand pipe and run all over the wood floor into the kitchen. With the current laundry tub both of these problems are resolved by a visual check of the hose and the fact that when the drain starts to fill up with lint you can see it and clean it out. With the Standpipe design its all hidden.

Soo, what I proposed was to have an overflow into either a straight pvc pipe to the basement or a secondary trap.

Additioanlly the homeowners do not want to have to pull ther washer out from under the counter to have to clean or trap, nor would like to visually see this trap.

Location of trap i Understand has to be in the same room, why, I dont know, I guess ease and visual for inspector and new homeowners.

As a secondary question, what frequency if any will a 2" trap need to be cleaned out - if the answer is never then were ok, otherwise its unacceptable. Case in point most bathroom sinks trap the hair on the bowl area, most traps in these areas almost never to be touched.

Third question is soap bubbles, even with a max standpipe, can the soap bubbles comeout and ruin the floor? Thats another reason I proposed the sealed washer connection with an overflow to the basement.

The plumbing will happen one way or another, I would just like to stay at code and come up with some assurances or options for these concerns.

Thanks

[The Builder]

Whenever theres a clog then the drain will have to be cleaned. As far as how often, it depends, but for my it has not been often in most of my calls. Also you shouldn't be having bubbles or water going on the floor. Its also good to have a 2 1/2 trap for laundry drains

[LazyPup]

i would certainly like to know where you get a 2-1/2" trap. Although they do make 2-1/2" pipe there is no 2-1/2" pipe listed as DWV compliant.

DWV pipe is 1-1/4", 1-1/2", 2" then it jumps to 3"

[JCM5]

Thanks for all the input

As far an 2 1/2 trap I guess you can use sch 40pipe glue up your own.

I plan on the 2" trap with the 2" stack at wash machine height ~ 36"

Again thanks for all the input.

Buy the way I downloaded the 2006 Plumbing codes and I must say I hate the way its set up. I personally would like to have seen pictures and examples like what we are talking about. There could have been a general section on items like these, im sure theres not too much variation in what we are talking about.

Again thanks for all the help

[pushkins]

I was wondering where the 2 1/2" trap was available as well?