We live in the first story of a 3-story building in which each story is a condo. The three laundry areas are positioned above each other. Each washer empties into a 2" standpipe (complete with p-trap) which then empties into the common 3-unit standpipe (larger). Our washer works fine, but sometimes suds from the other (higher) washers flow freely out of our 2" standpipe, making a mess of the laundry room. We are unable to reduce the amount of detergent being used in the other condos, so we are asking for possible plumbing solutions. Thank you for any ideas and/or solutions.

How old is the building ? Are the other first floor occupants have the same issue ? It sounds like there may be a partial stoppage. If the building was 4 stories a suds relief vent would have had to been installed by Mass code.

the first thing to do is have the drain snaked to make sure it is clear..

There may not be any "easy" solution because your unit is in the "suds zone" of the drain line and therefore it had to be installed properly to avoid that problem. If it was not installed properly, the solution is expensive because the floor would have to be broken into and the piping revised.

Was the building built as a condo or is it a converted apartment building???
2" inch stand pipe is not big enough and combined with the other units is way to small to handle the suds produced by the machines. Keep in mind that it only takes one condo member on the top floor to use too much soap to mess it up for all.
I'd bring a licensed plumber in to evaluate your lines and make recommendations that meet local codes.

Best Wishes

FIRST of course the existing drain pipe should be properly designed/clean/clear and in proper operation, in which case all is well and nothing else needs to be done.

Not a plumber.

I don't know if following is code approved -- but following concept is "similar" to what is used on dishwasher discharge lines. (Note that I don't recall EVER seeing the following recommended and "I" would like to know "IF" this has "ANY" chance of being code approved.)

Washing machine plastic/PVC Siphon break kit (Amazon) Whirlpool part 285834 aprox $25.+ Attachment fittings to existing stand pipe. (Also - more likely available in appliance stores / departments than actual plumbing department.)

"NORMAL" INSTALLATION:
Wash machine discharge hose attaches to inlet of siphon break. Another (or cut) hose attaches to siphon break outlet. The siphon break is normally used when a long discharge hose goes to a floor drain/laundry sink etc. In that case the first hose and break are installed at a high level (above machine fill line) and the additional drain hose then drops down to a floor drain/wash sink. The break then prevents siphon of water from washer to floor drain/sink.

------- OR see following ------ (May/May not be code approved -- I don't know, but would like to know) ------

HOWEVER To prevent overflows from drain standpipe due to ---"whatever" ----- Install MECHANICAL connections to existing drain standpipe top opening depending on situation. "Example" Combination of PVC reducer bushing/fittings with short PVC nipple. "Final" nipple designed with hose barb to insert into short hose between siphon break discharge and stand pipe fittings. Plastic siphon break MUST have mount/hanger etc attached to hold SECURELY in place --- When break is firmly (mechanically) attached to standpipe, wash machine discharge hose weight/pull could put much stress on siphon break possibly causing failure of break/fittings.

When wash machine is NOT discharging water - the siphon break will allow air to enter, the water level will then drain down within the drain standpipe to the fill line of the code required P-trap.

In low drain flow / partial drain blockage situations:
This system will prevent overflow from drain standpipe to floor caused my your OWN machine's discharge. Your own machines "forced" pumped discharge may even help clear/keep drain pipe clean of lent etc. In Condo (Not rented) situations other persons discharge "may" attempt to enter your machine (in lieu of overflowing onto your floor). It would depend on many factors --- but which would be better? IMO in most situations all inadvertent discharge would be blocked.

BUT: As asked above --- Would it be code approved? (I standby for 40+ lashes)

That may just be jibberish. A washing machine drain hose connects by means of an "open" drain with the hose hanging in to it. Somewhere in that treatise, it may say that you are describing a "solid" connection with a check valve, and an air gap ahead of it.

Sorry you read my post as "jibberish" or maybe "gibberish".

It was intentioned to provide a answer to the fairly common problem with overflowing of wash machine drain standpipes often causing damage to floors, excessive clean-up etc. Although my suggestion WILL work -- and it WILL leave a required AIR GAP in the standpipe between the drain P-trap and the top of standpipe -- the question is - NOT - does it work - BUT - Does it violate any code? I don't think it can be denied that with the present use of a open drain standpipe overflows happen.

I suggest you re-read my post.

At NO point is there mention OR suggestion of a check valve or could be in any way be interpreted that way. Because my cheap and easy workable suggestion IS "Out of the box" --- I thought I had to write a "treatise" in order to fully describe using a direct "SIPHON BREAK" connection to prevent overflows from the presently used " open drain with a hose hanging in to it".

FOLLOWING IS THE SHORT VERSION OF MY SUGGESTION:

------------------------ BEGIN SHORT VERSION -----------------------------

1. Obtain a SIPHON BREAK model Whirlpool 285834 (or 76660) - (NOT a check valve). (Google or Amazon check it.)
2. Insert washing machine discharge hose into siphon break INLET side.
3. Insert another very SHORT piece of hose into the siphon break OUTLET.
4. Make a "Mechanical" (Solid) connection to the " open " top of the wash machine drain standpipe (From the short hose -- to the drain standpipe.)
5. The connection in (4) above would be made using bushings/adapters/PVC pipe etc.(depends ENTIRELY on just what exists and is needed) with the "final" required connection a short piece with a "barbed" end which would insert into the short hose attached to the OUTLET side of the siphon break.

7. Extremely short version is: Wash machine discharge hose (to) siphon break (to) short hose (to) required fittings to CONNECT to top of drain standpipe. (NO check valve.) Installation of Siphon break STILL allows and WILL establish air break.

------------------------ END SHORT VERSION -----------------------------

Following reiterates what is accomplished by above:

The wash machine easily has unobstructed discharge into the standpipe. --- No standpipe overflows -- No damage floors, unexpected clean-ups etc.

"IF" the drain is "partly" blocked the discharge will continue --- and NOT overflow from the top of a " open " standpipe. (Because the standpipe is NOW "Mechanically" / "Solidly" closed -- "EXCEPT" for the siphon break.) "IF" the drain is "totally" blocked you are --"SOL" ------ pretty much the SAME as "with OR without" the siphon break.

When the discharge is complete -- the siphon break ALLOWS AIR TO ENTER the standpipe -- and there IS a AIR GAP now established between the water in the drain P-trap and the top of the standpipe.

As to the OP, this WILL prevent the neighbors "suds" from overflowing the drain standpipe --- which is no longer a "easy" path for back flow.

Treatise -- a book, article, etc, that discusses a subject carefully and thoroughly - (Thanks for the compliment) -- Wrap up:
The question remains -- NOT -- Does it work -- BUT even though a air gap IS maintained within the standpipe -- Does it violate any code?

Without a " check valve" even with a "solid connection" to the standpipe, a backflow condition will either overflow the "air gap" or fill the washing machine, neither of which is a desirable condition.

Sincere thanks to all of you (Plumberpalmer, packy, hj, Wheelchair, and WC) who responded to my "washer suds overflow" query. There is something noble about strangers reaching out to help others. I'm not sure how the final solution to my problem will evolve, but (thanks to you) I feel much better prepared to rejoin the battle.



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Really (I am) sorry for long posts taking my AND any readers time, but I don't just don't know how to explain the point any other way.

THE KNOWN PROBLEM
Most back-flow/overflows from a wash machine " open " standpipe happen DURING the use of the machine discharging into the SAME drain. (Because the drain is "partly" blocked with lent etc OR a new machine has a very high discharge rate.)

SOLUTION FURTHER EXPLAINED
In a "single unit" house it is improbable that a "high pressure" back-flow from some OTHER source could/would force itself back into the wash machine. The siphon break itself is "self sealing", similar to a AAV. ----"IF" in the VERY unlikely event any small amount of back flow from a source OTHER than the wash machine could pass back thru the machines internal valves --- solution --- add bleach to machine and run a empty wash cycle.--- Note that with just a " open " drain the back flow WOULD have been all over the floor.

Even in a multi unit building IMO the siphon break (of the type discussed) would block OTHER units discharge which IMO would not likely be under much pressure --- certainly NOT just "soap suds".

BACK TO ORGINAL PROBLEM
The OP is in MA which does not allow owner plumbing work. So in lieu of MAJOR pipe modifications to solve the LOW/NO pressure "soap suds" discharge problem, it would have to be determined "IF" a professional installation of a siphon break (as discussed) would be allowed by code. A unbiased plumbing inspector would have to make the call --- NOT someone who would prefer to make a $xxxxx repair.

A LITTLE HISTORY
30+ years ago, --- long before helpful information was available on the Internet, I had a wash machine overflow problem. It was because my house had a two-inch CAST IRON drain more than 50+ feet long. Because of lent/minor table scraps, the drain would partly clog and a wash machine over-flow would happen. Installation of the siphon break COMPLETLY solved the wash machine standpipe overflow problem VERY well --- FOR YEARS. In later years the kitchen sink drained a little slower than I wanted (If it was very full) -- I then replaced the long run of cast iron with PVC at the same time I was making other modifications (with a permit).

CONCLUSION?
The presently used open "hook-up" design IS easy to install and use -- especially for renters etc. But messy wash machine overflows can and do happen with the present design. IMO There should be a BETTER solution --- and I guess it is up to the "Powers That Be" and some enterprising plumbing manufacture to come-up with one. "IF" / When they do - it will be a real money maker. Meanwhile "I" am very happy with the siphon break installation. It DOES prevent overflows, I have NEVER had a backup from another source into the machine, --- AND it allows a air gap within the standpipe.

'google':


SUDS PRESSURE ZONE




the areas marked 10 X and 40 X DIA. STACK (stack diameter) are the suds pressure zones to which other fixtures should NOT be connected because of the suds pressure from fixtures above

EVEN IF CODE PERMITTED the laws of physics still apply
This becomes a 'good/best practice' of which you are now (painfully) aware

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



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