Suds Relief for washing machine stacks?

[John McMullen]

Hello,

I don't belief the IPC lists "suds relief" or keeping a minimum distance of 8 ft from washing machine stacks (From other stacks). Only an obscure old reference from the UPC. I have never seen this called out on any plumbing plans. Only a slight reference to it recently brought it up in my mind.

http://forms.iapmo.org/email_marketing/codespotlight/2017/July6.htm
Is suds relief (the above code), still relevant at all?

What if there is a combined bathroom group stack with a washing machine tied into the common 4" sanitary stack (5 stories tall)? Is this considered a "suds stack"?

Thanks

 

[Zanne]

I just came across this while looking for info on suds relief. For some reason I thought it was 5' but I see this says:

From the 2015 UPC Illustrated Training Manual

711.0 Suds Relief.
711.1 General. Drainage connections shall not be made into a drainage piping system within 8 feet (2438 mm) of a vertical to horizontal change of direction of a stack containing suds-producing fixtures. Bathtubs, laundries, washing machine standpipes, kitchen sinks, and dishwashers shall be considered suds-producing fixtures. Where parallel vent stacks are required, they shall connect to the drainage stack at a point 8 feet (2438 mm) above the lowest point of the drainage stack.
Exceptions:
(1) Single-family residences
(2) Stacks receiving the discharge from less than three stories of plumbing fixtures

I'd like that translated into plain English. LOL.
So, if I'm understanding this correctly, suds relief is not needed in one story single-family residential homes?

Editing to add that if you have a high efficiency top loader the suds relief is apparently no longer needed.

IAPMO Plumbing Code Section 711-1: Suds Relief: Ever since the year 2000 all new washing machines and dishwashers come with front loading fixture doors which both require High Efficiency Detergents which produce no-suds. If they did the suds would become compressed inside the washing machine and dishwasher forcing the suds through the frontloading doors. This same section also lists kitchen sinks and bath tubs however they also use the new H.E. Detergents, but they could mandatorily use other soap items that could produce sudsing. This would also overflow the sink or bath tub. Very little suds would flow by gravity through the 1-1/2” size waste pipe to cause any real plumbing suds problems. Washing machines were the real problem with pumped water forcing the suds through a 2” waste pipe. Excessive labor & material costs for installing a Suds Relief Piping Systems in year 2020 Is no longer required. All the above sudsing information can be verified by all US manufacturers of detergents.