I apologize if this answer is here, but I haven't been able to find my exact situation. I'm in Idaho, putting a washer / dryer in on the main floor of a house built in 1907, because the old set was in the basement which is unfinished and has a scary flight of turning steps going down and my pregnant wife isn't excited about trekking down there to do laundry. The problem is, the only sewer line anywhere near where the washer will be is 1 1/2". We just bought a brand new high-efficiency LG Steamwasher / dryer. I have been reading the posts and most say that the pipe needs to be 2". Is this absolute, or could I get away with putting the maximum length of 1 1/2" pipe above the trap to give it room to drain? A home inspector that I know said that if I maxed out the length of the drain pipe, it probably wouldn't back up, and although it isn't code, it should work. I really don't want to put it in like that if it's going to back up, and I'm going to have to start over anyway. If I do the non-code solution (and I think I saw that 42" above the trap is max?), it would put the overall height of the box at 5 1/2 feet above the floor or so, because there is another line running to a sink that is about 2' above the floor. Aside from looking strange, will it work? The only other option I've thought of is to cut out the 1 1/2" pipe and run 2", but that would be a huge project that I would like to avoid (one of the joints is above the foundation in a very tough spot to reach). The pipe is located in what was formerly the exterior wall of the house (an addition was put on, so it's now an interior wall), and is vented to the roof. I apologize if I forgot any of the details, and thanks in advance for your help.
Kevin

Hi,

If I am not mistaken that Idaho follows uniform plumbing code in your state.
To answer your questions, a washer drain rough in must be 2" minimum drain and the max. length on a trap arm is 5 feet long. Washer box can be a height you want as long as trap height is 6" from floor, standpipe from trap to washer box is a min. 18" to max 30". This is code for uniform plumbing code and would highly suggest to do it the right way. " Like they say measure twice cut once."

Also on your 2" trap arm which is from trap outlet to santee drain in wall, use a maximum of 90 degree offset as it states in code book. THANKS

Quote:

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Originally Posted by ;

as long as trap height is 6" from floor, standpipe from trap to washer box is a min. 18" to max 30". T

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I never could understand this, but then there's a lot of stuff in UPC I don't understand.
In my area ( SPC) we install the trap as close to the floor as possible and make our standpipes a minimum of 36" from the trap. Having said that you're asking if a 1 1/2" drain line will carry your washer discharge. Although it's best to install by code I understand your problem.
Will it work? Most likely it will.
I have a older home with a 1 1/2" trap and drain. Because of the more powerful washer pumps you may overload the pipes. How I got around this was to connect the washer hose to the stand pipe making it a closed system. You can do this using a compression fitting, (see image) or simply duct taping the hose to the pipe. Good luck, Tom

Back years ago 1.5" standpipe was legal, but it has change because of draining issues. For example, you don't have equal atmospheric pressure on the inlet and outlet of fixture on w/ Laundry in it and its pretty pretty much sealed.

UPC AND CPC has annual inspectors congragation through states that adopt UPC AND CPC to improve plumbing installations , etc. THANKS

Thanks for the imput argaiu1017 and welcome to The Plumbing Page. I may kid you guys out in UPC land because your code forces you to work a little harder and do stuff that *I just don't understand. For example whay is the washer trap held 6" off the floor when that 6" could be better used on the standpipe? And why oh why do they mandate a counter top air gap when they give so much trouble. Seems to me a high loop would be a much better choice. We have had many, many complaints on countertop air gaps but not az single high loop complaint in all the seven years that I've been here. And my company has yet to receive the first complaint from the hundreds of high loops that we've installed in our condos band houses. Now don't get all defensive on me. I think UPC goes the extra mile in protecting the homeowner. It's just sometimes I think they are over protective.
( I will go into my bomb shelter and wait for blast that you and Milo are going to send my way) Once more welcome and have a great weekend. Tom