Plumbing in new washing machine - drain is 1-1/2" pipe

[hombrewdude]

My old machine was routed direct to the laundry sink. I bought a new machine, and I want to get the plumbing out of the sink..

All of my drain pipes in my 30yr old house are 1-1/2" ABS

My kitchen sink drain runs directly behind my washing machine Sink is upstairs, machine is in the basement.

so...

I plan on adding a 1-1/2 tee near the floor Off the T a p trap Off the p trap a standpipe - taller then the washer machine Then attach the washer machine hose to the top.

Any problems with this? I have read I should have 2" drain pipe. but all of my pipe is 1-1/2"

[Eric in North TX]

Works for me, if you ever have a problem with it, you could Rube Goldberg in some more pipe just to have a reservoir. I'm pretty sure mine is all 1 1/2 and it works fine.

[Edwin Pawlowski]

Mine was in the house and 1 1/2" has worked for the past 28 years.

[Speedy Jim]

It won't be "correct". The new trap will not be vented and waste flow from above can suck the trap dry. You *could* add a mechanical vent to the new trap.

If the kitchen trap doesn't have a vent, it will surely gurgle when the washer empties.

Jim

[woodarama]

my situation was the same as yours and the kitchen sink did gurgle when the washer drained.how i fixed this was to put a t and a short piece of pipe on the kitchen sink drain and a "ventless vent" sold at hd for places that don't have a vent.basically its a oneway fitting that lets air in but not out.

[Bob F]

I believe code for a washer without a tub is 2". I know of one case where 1 1/2" was used, and significant rot was caused by frequent small overflows over a period of years.

Bob

[hombrewdude]

What is the best way to add a vent? I have never seen one of those for sale before. Does it have to be on the kitchen sink?

I also have the option to tie into the drain line for the laundry sink. It is next to the washer. The gurgle won't be a problem there.

Speedy Jim wrote:

[hombrewdude]

I am in the basement. If there is a problem, I can just pull the hose and put it back in the sink.

I d> > My old machine was routed direct to the laundry sink.

[Speedy Jim]

Several vent styles:

has the Oatey "AutoVent".

Jim

[Bob F]

If you are still going to have the sink, You could have a "Y" in the pipe you are adding, with the second side going to your sink to make sure any future overflow goes there rather than the floor. The "Y" would be a ways under the top of the pipe where the washer hose comes in.

You are right about 2" into 1 1/2". Code would be 2" for the whole drain.

Bob

[Robert Haar]

We have one from a company called STUDOR. It is on the drain from a kitchen sink in a free standing island - no vent stack anywhere nearby.

[hombrewdude]

This seems like more work then it is worth... And I really don't want any overflows.

Whats the best way to route it into the sink??

Robert Haar wrote:

[BillGill]

I checked all the responses. I don't have the 1 1/2" problem, but when I moved in the washer had been backing up periodically for years. I got tired of it and had the drain replaced. The plumber offered to do it the cheap way. He punched a hole in the foundation and ran the new drain through that. The whole drain assembly is exposed. He added a vent by running the vent pipe up the wall about 7 feet and putting one of the one way valves on top of it. So if you are in the garage you can do it that way.

I have also seen sink draings vented using the same technique under the cabinet. I expect the vent needs to be above the level of the trap.

Bill Gill