Plumbing Trap/Vent Question - DIY Chatroom

SteveSmith98 · 01-12-2009, 05:06 PM

Hi,

I'm moving my washing machine and need to install a new drain. It's only moving a couple of feet. Currently it drains into the sink.

I don't think I can extend the drain line with exceeding code (trap arm length). The existing run is about 3 feet, and I'd be adding another 4 feet or so.

I was talking with someone and they suggested instead of a new drain line with a P-trap near the washer, I just add the drain line as if it were a new sink on the same P-trap (i.e., join in above the existing P-Trap, not before) so I don't need a new vent.

This made some sense. I can't seem to find anything that tells me the maximum distance from a P-Trap to the actual fixture, other than to say it should be close.

I'm in Ontario, Canada for code purposes.

Thanks!

Mike Swearingen · 01-12-2009, 06:52 PM

You need to make a call to your local Building Inspection Department to find out about local code, permit and inspection requirements.
Then you'll be sure, and you'll have a record of doing it right.
Good Luck!
Mike

zosoplumber · 01-12-2009, 07:13 PM

You cannot extend past 6' from vent, but your washing machine drain should be 2" pipe, if the line your pulling off of is 1"1/2 drain from your sink you'll just run into problems.

SteveSmith98 · 01-15-2009, 09:29 AM

Thanks everyone.

I've checked around a bit and it seems the expected install method (in Ontario) is indeed above the trap. I don't know if it's required this way by code, but I found an online code cheat/study page that describes this.

Zosoplumber: The code also says 1 1/2 pipe is the requirement. I expect that 2" pipe would be much better, but I don't have an option there, as I'm plumbing into the vertical-portion of a circuit-vent, which is only 1 1/2". So, I'd have to dig up the entire floor and re-run the entire drain to get to 2" pipe or larger.

Instead, I figure I'll install the standpipe so that the top of the standpipe is higher than the laundry tub it's connected to (above the flood rim, I think is the code-way of saying this?) which should help ensure that any backup ends up in the sink rather than coming out of the standpipe. I'll also use one of those rubber gaskets to connect the washer outlet to the standpipe.

Finally, I'll take care to make sure the washing machine drain water doesn't have to do much directional change, etc.. I realize this isn't ideal (the 2" drain would be better) but I'm hoping these steps will still give me good performance (no overflows).

Any comments here? Any other steps I can take?

Alan · 01-15-2009, 11:19 AM

It sounds like you want to tap into the tailpiece of the sink to drain your washer? ? ?

Can you provide a diagram?

SteveSmith98 · 01-15-2009, 01:25 PM

Alan: If I understand what you're saying, then yes that's correct.

I've attached a diagram. The source is: http://www.3dplumbing.net/ontplumbin...appliances.htm

As far as I can tell, that's the way to do it if you have a laundry tub nearby (which I do).

zosoplumber · 01-15-2009, 11:22 PM

I see what your saying, nice pic. I could see you being able to do that since its a mop sink(laundry sink). Didn't know that. If the flow is too much for the line it will relieve itself in the sink. Not aloud to use 1 1/2" drain for washing machines here.