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Laundry hose connected to drain pipe

viliam's picture

Hi, I'm Viliam's  wife. Can you please help me settle a little dispute. I would like to connect my laundry drain hose directly into the sink's drain pipe, because I hate it having to stick into my laundry tub. All for aesthetic reasons. I would like to put in a nice counter with a nice sink, etc. and have the hose concealed in the cabinetry. this O.K.?

Some plumbers (and V.) say that it's not good ,what for?...and others say sure go ahead.

What is the forum's opinion on this?

Am I crazy for wanting this?

Help meeeeeeeeeeeeeeeeee.............................,

Dazed and Confused


P>S> You guys sound like you have a lot of fun here at Breaktime.

How many girls belong to your club? this  just a guy thing?

(post #57322, reply #1 of 28)

I think there would be problems with backflow prevention. You need an air gap. Also, the washing machine pumps out the water real fast and it might be too much at once for the drain line. So the tub holds the overflow until it has enough time to drain out.

~Peter    the former maintenance person

PS There are a few members of the female persuasion around here like Pi, Theodora, Jencar and Roscumom. But the biggest restraint on language is the evil Prospero.

Where am I going and what am I doing in this handbasket?

(post #57322, reply #2 of 28)

Depends. My Bosch washer manual says it is okay and even shows a diagram how to do it with a tee on the sink. The hose does have a bend in it that rises up to just below the bottom of the counter top. Been working fine for more than a year.


bit Just because you can doesn't mean you should.

(post #57322, reply #6 of 28)

I like your answer Bitman. This is the one I like to hear. But see.........there are many people out htere that tell me otherwise and that is why I am confused.

We just renoed the basement and am all excited planning this gorgeous laundry room. From a design point of view sticking a hose in the sink just doesn't cut it for me.

I am  going to try to draw my plumbing configuration and get my daughter to scan and post it for all of you, so I can get everyones blessing.

After all the work we've done I'd sure hate to screw things up .



The anarchist gardener/renovator

(post #57322, reply #7 of 28)

Current standards for the installation of a washing machine drain are:

A. Hook the hose over the edge of a laundry tub. 

This allows an air gap between the hose and the sewer drain. Secondly it allows the pressure/volume of the discharge to be relieved in the space of the sink. 

If the washer hose is hooked directly to an 1-1/2" side outlet tee above the p-trap then the pressure of the discharge can force the slip joint connections apart and you would find your wash water in the floor. 


B. A 2" diameter stand pipe with an opening at 42" height above the floor. The 2 "stand pipe is cemented into a 2" pvc trap which then p-traps into a sewer drain with a vent connection within 5 ft.

Depending on how your laundry tub is plumbed you may be able to accomplish format B. by replumbing same.    Just remember to use all cemented connections and keep the staandpipe height 6" above the flood level of the washer.

If this is clear as wash water....let me know and I'll hunt up a reference picture to send.


....................Iron Helix


Edited 6/15/2003 7:50:07 AM ET by Iron Helix

.......Iron Helix

(post #57322, reply #8 of 28)

while we're on the subject....

about fifteen months ago we moved from a house on the city sewer (OK- with the plumbing drains connected to the municipal wastewater system- but come to think of it, we did have some really disgusting lowlife neighbors on one side of us.  last week i talked to the guy who bought our old house- he said those losers now have a sectional sofa on the front lawn - no kidding!  man, are we glad moved- but i digress) to a house on a septic system.

in the former/old (70 yrs) house we had the washer drain into the laundry sink with a section of pantyhose wired over the hose as a lint filter (old house, old neighborhood, big trees, clay lines, etc. -just trying to avoid getting on roto-rooter's xmas card list like all of our neighbors).  so we figure we should be equally careful with the septic in the new house, right?  only there isn't a laundry sink- just one of those hookup/drain box inserts in the wall.  so i very securely wire the pantyhose to the washer drain hose and feed it down into the drain box opening.

wellllll........ with the very first load the pantyhose filter swelled up and blocked the drain pipe and flooded the #%**&#% laundry room and adjoining garage! (we also found out that whoever had floated the garage floor was unfamiliar with the concept of water running downhill)

so, any suggestions for mitigating the lint problem with this type of set-up?  the laundry room redo will include a sink, but that's probably at least a couple years off.


(post #57322, reply #10 of 28)

If you do a Google search on the topic of laundry discharge lint, you will end up with plenty to read, especially on how modern synthetic fiber lint can clog up a septic field in no time.

Many newer homes with PVC plumbing and a straight path between the laundry drain and the municipality sewer lines would hardly encounter the laundry lint clog, but there are plenty of older homes that get renovated with fancy laundry room suites, etc. that doesn't seem to take this into consideration, and the older drain lines weren't necessary designed to handle modern lifestyles.

After sifting through the information, the most sensible solution (for our household) seems to be a deep laundry/utility sink with the discharge hose hung 'above' the rim of the sink. (Our local code requires this).

At the moment we have a standpipe (glued, no slip joints) following the washer manual specs.

Some sort of lint fitering scheme should be part of this setup, ranging from stocking over the hose to a lint trap on the sink drain.

There are some costly filtering options available but for our household that would be an unnecessary overkill.

We already have a diciplined routine of keeping the dryer lint screen clear with every wash/dry session, so it would not be an inconvenience to do the same with the washer discharge.

(post #57322, reply #11 of 28)

i would install a laundry box with its own standpipe for a washer drain. standpipe should be 2" and 42" vertical drop to accomodate amount of water from washer without flooding. i would install a cleanout tee at the bottom of standpipe with cleanout accessible from outside. and i would install a removable p-trap and a grey water drain from the washer, especially with a septic system, don't run it into the septic, run it out into the yard somewhere, preferably to a holding tank you can use for irrigation. in cali we don't need to worry to much about freezing, in different climes, this needs to be addressed. also there are no women allowed in here, don't ever let it happen again!

(post #57322, reply #12 of 28)

Viliams wife here again!


Ok. So I just spoke to someone and thay said "why cant't you hook up laundry hose just like a dishwasher  ?"

and I go "Yeaaaaaaahhh!    Why can't I?"


The anarchist gardener/renovator

(post #57322, reply #14 of 28)

There are many ways to hook up a dishwasher.  Which way are you referring to?

Here is the big question... are you wanting to know how to do it correctly, safely, and to code?

Or are you wanting to see what you can get by with no matter what is safe and meets code?

Not judging.  Just asking. 

Just because it drains doen't mean it is safe.  And do yourself a favor... ask your advice from people who know what they are talking about.  There are too many yahoos here and other places who try to come across as experts while spouting off incorrect or dangerous advice.




Edited 6/19/2003 1:03:52 AM ET by Wet Head Warrior


(post #57322, reply #15 of 28)

Here is my situation,

Over the winter my husband  and I renoed the basement.  One of the rooms is my laundry room. My dream laundry room.  Because I hate seeing hoses , etc. showing

I have or attempted to hide as much behind the wall for aesthetic treasons (this is a typo, but I'm keeping it!).  All my cabinetry ,sink, etc. will be going along a 12 ft wall, including built in washer and drier, so I will have one long counter to fold the clothes.

I will attempt to describe my plumbing situation.

Here it goes:

In the left corner is my main drain pipe coming vertically down from the floor above(kitchen and bath) which is copper and 6" diameter.

Into copper drain I have a 2" pvc pipe connected horizontally going about 8' (hidden behind the wall.)

At the 4' point I have a "T" in the line sticking out of the wall to hook up my sink.

At 6' I have a "Y" put in the line with one arm sticking out for the washer drain hose connection.

At 8' is the end  of the pvc line to which is connected a 1" hose running from a condensate pump connected to my furnace  for the  humidifier and a.c.  drippings. This is all behind the wall for another 6' and then it's open in the furnace room.

Oh, I almost forgot! The hot and cold pipes are recessed into the wall behind the washer hidden from view.


This is my situation .

All the dry-wall work is complete.

Please don't tell me to break open the drywall or I will cry. I've even primed and painted the walls.

The anarchist gardener/renovator


(post #57322, reply #23 of 28)

Dishwasher - no, at leastnot the way we do them in Ontario with a 1/2" fitting at one end, a dishwasher has a much smaller hose and pushes the small amount of water it uses through it at a much slower rate - a washing machine has several times as much water in it, a much larger hose, and the water comes out of it at pretty good pressure.


Phill Giles

The Unionville Woodwright

Unionville, Ontario

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Phill Giles

The Unionville Woodwright

(post #57322, reply #24 of 28)

So...........I have to install a standpipe. O.K.

But my counter height is standard 36" and I want all this "stuff" hidden under it,because my heart is aching for a built-in washer and dryer. By "built-in", I mean under and part of the counter.....or I mean the counter going over it..just like a dish washer. Get it?

You guys are saying it has to be at 42" height or above the rim of washer.

How bad can it be to be only a little 6" shorter?   (maybe I should rephraise that!)



The anarchist Gardener/renovator

(post #57322, reply #25 of 28)

I thought standard appliance height was pretty close to 36" already ? With the Frigidaires, you have to buy a special top for the appliances in order to truely build them in. In any case, my sink cabinet is 36" and the pipe is inside - I don't know about the 42" - check with a dealer (e.g. Home & Rural) about you need.


Phill Giles

The Unionville Woodwright

Unionville, Ontario

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> 

Phill Giles

The Unionville Woodwright

(post #57322, reply #19 of 28)

In all my years, option B is the only thing I've seen, except where people have those ancient portable washer/spin dryers.

I've never seen a full size washer drain into a laundry sink.  Just make sure that the pipe is 2" dia, and the top is above the height of the rim of the laundry tub.  Might make it harder to hide, but it's possible.

To refresh,

B. A 2" diameter stand pipe with an opening at 42" height above the floor. The 2 "stand pipe is cemented into a 2" pvc trap which then p-traps into a sewer drain with a vent connection within 5 ft.


(post #57322, reply #22 of 28)

Oh, you'd be surprised at how many folks have those free-standing concrete, steel, or even plastic laundry tubs in their basements and just didn't see the need of adding plumbing for their washing machine. For us, it's just an hour's work to add a standpipe; for a lot of folks it would be a visit by a plumber and a couple of hundred $$$'s


Phill Giles

The Unionville Woodwright

Unionville, Ontario

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> 

Phill Giles

The Unionville Woodwright

(post #57322, reply #26 of 28)

Most free standing washer dryers have a top set at 36"height, but the control panel is taller by 6" or 8", which would put the top of the standpipe at or below the control panel level.  Most free standing installations are not at countertop depth due to hoses, ducts and do you have custom appliances?

After reading your layout description I have two questions/comments.

1. Where is the vent stack for the longer than 5' distance from the main? Current standards ask for a vent to be present when the drain is more than 5' from a main stack.

2. How is the condensate pump connected to the two inch drain? Current standards require an air break between a condensate drain and the sewer line to prevent a cross connection.

Best Regards on the decorating's tough to make a washer/dryer box look chic!



....................Iron Helix

.......Iron Helix

(post #57322, reply #27 of 28)

Most of the major lines of appliances now feature machines with the controls on the front panel so that the machines can be stacked; as a result, these machines can also be semi-built into the base cabinets (built-in, in this case, just means that the counter can be extended over them). The brands I've seen require a special replacement top panel.

You mention "condensate pump". Is that for a gas dryer ? I've only ever seen condesate pumps on furnaces and water-heaters.


Phill Giles

The Unionville Woodwright

Unionville, Ontario

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> 

Phill Giles

The Unionville Woodwright

(post #57322, reply #28 of 28)

You might want to check out this site:


bit Just because you can doesn't mean you should.

(post #57322, reply #9 of 28)

doesn't make it safe or code legal just because it is in a manual.

Rats!  I gotta sell my entire collection of Fine Homebuilding magazine.  Issues 1 through 150!  So I decided to put it up on eBay.  They are being sold in lots of 10.  All lots start at 99 cents.  So get on in there and pick yourself up a bargain or two...

Check it our here... FHB on eBay


(post #57322, reply #3 of 28)

You may not want to dump laundry machine discharge straight down the drain - the utility sink arrangement may actually serve a good purpose for reasons I will explain.

In the last day or so I've been researching the topic of laundry washer discharge and the amount of lint it contains, which turns out is quite a lot.

I have a friend who had to call a plumber to dislodge a lint buildup in the waste line 6 feet outside his house where there is a 90-deg turn.

I am now experiencing a slow drain and discharge water backing up the washer drain standpipe, presumably from lint buildup.

The reason I mention this is because this doesn't seem to be a widely recognized problem that creeps up on folks at some point.

As a preventive measure I am going to install a utility sink and hang the washer discharge hose above it and filter the discharge water before it enters the drain.

One thing I read during the course of the Google search is modern laundry discharge contains larger amounts of synthetic fibers from garments such as Polartec jackets.

For folks with septic tank and leach fields, the synthetic fibers can actually clog a septic field in very short time.

(post #57322, reply #4 of 28)

All the houses I have seen, if they were plumbed for a washer/dryer connection, have a box in the wall that has the hot & cold connectionsd and a place to insert the washer discharge hose into the open end of a pipe.  Never have seen one dumped into a separate sink.

Ms V...why don't you sign in with your own name?  That way we can tell if it's you or him, and we won't tell dirty jokes to you :)


Do it right, or do it twice.

I'm sorry, I thought you wanted it done the right way.

(post #57322, reply #5 of 28)

If you hook it up directly, it will such all the water out of the washing machine after it first discharges the water.  A seperate washer stand ppe can be installed, directly behind the washer, so it doesn't show.

Most women would love the laundry sink you have.  They use it to soak his dirty clothes, a place for washing a mop and some drains need it because they drain so slowly.

(post #57322, reply #13 of 28)

Why not (unless your area has some wierd regualtion against it), our last house was done that way, this house is done that way, virtually every house in the whole area was done that way. A tee comes off the laundry-room sink and has a verticle stack up to near the top of the cabinet; the hose goes through a hole in the side of the cabinet and down into the verticle stack.

EDIT - I see from the positioning of this note it looks like I was answering the "dishwasher" question - this note answers post #1


Phill Giles

The Unionville Woodwright

Unionville, Ontario

Edited 6/19/2003 2:37:52 PM ET by Phill Giles

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Phill Giles

The Unionville Woodwright

(post #57322, reply #16 of 28)

Howdy neighbour!

My husband Viliam and I live in Oakville, Ont.!

If you say yours and all the houses in your area are hooked up that way then it must be to code. I have a feeling I am going to have to put in another pipe under the sink like what you described. So if its to code in unionville then it must be O.K. (and to code) in Oakville.



The anarchist Gardener/Renovator

(post #57322, reply #17 of 28)

I saw one of those laundry tub when I was on vacation in Detriot But down here in the gulf coast you could not buy one if you wanted. I do not think Hd even sell them here. Everything here is 48 standpipe behind the machine. The one in Detriot was the first one I saw in over 30 years

(post #57322, reply #20 of 28)

I have an add-on laundry drain system because of the age of the house there was no provision for laundry drainage. The standpipe is behind the washing machine and connects to the drain, above the trap, of a utility sink next to the washing machine. The outfall of this drain is a separate tank and small field in the back yard.

The utility tub acts as a catch basin because the rate of discharge from the washing machine can overwhelm the capacity of the drain pipe. This hookup is similar to what is used with a dishwasher.

I should note that if you connect to a drain field instead of the city sewer system you should have a holding tank that can be accessed and cleaned, like a septic tank, and the outfall from the tank should be similar to that of a septic system so that the solids that are in the water settle rather than clog and cause the field to fail. You'd be surprised at the amount of gunk that collects in the bottom of the tank over time.

(post #57322, reply #18 of 28)

If you say yours and all the houses in your area are hooked up that way then it must be to code.

Bad assumption - code folks don't always get it right or even check everything.

If this is a renovation - use a 2 1/2" standpipe - code coalls for 2 but some newre washers need 2 1/2 because of their high discharge rate.

Why not do it like a dishwasher?  Because it's not - higher rate and pressure of discharge. 



10 .... I have laid the foundation like an expert builder. Now others are building on it. But whoever is building on this foundation must be very careful.

11 For no one can lay any other foundation than the one we already have--Jesus Christ.

1 Corinthians 3:10-11

======================================== "Man's capacity for justice makes democracy possible, but man's inclination to injustice makes democracy necessary." Reinhold Niebuhr: 'The Children of Light and the Children of Darkness' ========================================

(post #57322, reply #21 of 28)

Do you have any friends in your area or in Mississauga with a newer home ? They will surely have the same setup, the washing machines sold here are all equiped for this type of installation. Only key ,as everyone has mentioned, is that the standing pipe needs to go to nearly the top of the cabinet and the hose has to form an upside-down "U" as it enters the standpipe in order to ensure a syphon break.


Phill Giles

The Unionville Woodwright

Unionville, Ontario

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> 

Phill Giles

The Unionville Woodwright