Washing machine drain question

mlbhvwisp · Nov 14, 2009

Here's the deal. When we had our house built, I had asked the 3 stooges contractors to install a drain for the washing machine in the basement. It works but......I believe the trap is larger than the PVC pipe going into the drain. Now, when running the washing machine excess water comes out of the drain into a temporary (6 years) bucket to catch the extra water.

Question of the day.
Can I install a new drain into the side of the main line instead ot the top of the drain? I will be using a trap and all PVC will be of the same size.
Or, do I just install a new one on the top using the same size PVC and will that clear up the issue?

ps. That is as high as my drain hose will run. If I need a longer hose and taller drain pipe, I could do that also.

Thanks in advance.

Gary Swart · Nov 14, 2009

I see at least 4 problems, pros may well see more. First, you have an illegal S trap, not a P trap. Second, the drain is reduced in size where it enters the main drain. NEVER reduce a drain size. Third, the tee in the drain is the wrong type, and fourth, the standpipe should be at least 24" high. This may be a problem depending on your washer's pump capacity to lift high enough. I'd say the main reason for the overflow is the bottleneck created by the reduction at the end of the S trap. I'd also get rid of the trap with the plug in the bottom.

Sponsor · 2022-01-29T12:20:58-0800

mlbhvwisp · Nov 14, 2009

Gary,
I appreciate your input. I plan on replacing the existing trap entirely. I have an new directional tee that I want to know if I can install it so it goes into the side of the drain as opposed to the top of the drain. I also have 1.5 inch P Trap and coresponding pipe to use.
Am I on the right path?
Do I need to go with 2 inch?
Thanks!
Mike

Gary Swart · Nov 14, 2009

Washers require a 2" drain. That's at least part of your present overflow problem because after the S trap (illegal) your drain is choked down to 1-1/2" before it goes into the tee. Part of what needs changing is the 2"x2"x1-1/2" tee. Yes, put the tee on it's side and that will eliminate the S trap, but as I said in my earlier answer, you NEVER reduce a drain line. You can stay the same size or go bigger, but never smaller.

mastas · Nov 14, 2009

the u looks backwards to me too...if that makes a difference.

Terry · Nov 14, 2009

All of the fittings in the picture are wrong here.

The washer trap and standpipe need to be 2", and the trap needs to be vented.

Santees can be installed vertically, but not horizontally.
For that, you need a wye fitting.

mastas · Nov 14, 2009

I'm guessing, since I can't positively tell from your picture, but I'm about to setup a secondary w/d in my basement. I was trying to figure out how to safely add a standpipe since the house main is around 4' high so I decided I'm going with a closed system. You might have to do that too. If you have a blockage after that branch, it's gonna dump there.

hj · Nov 15, 2009

drain

Whoever installed that washer drain was NOT a plumber. Everything about it is wrong, and just connecting the washer to the side and not the top is not going to fix everything. One problem that will NEVER go away is that if the drain becomes even slightly obstructed the sink drain water is going to overflow the washer's trap. The standpipe must be long enough to build up some hydrostatic pressure before it fills up and overflows. That tee you show is either NOT a directional tee, or it has an internal baffle which will create IMMENSE flow problems in the future, not to mention making it impossible to snake the drain when it happens. DO NOT use a tee, use a "Y" or "combo".

mlbhvwisp · Nov 15, 2009

I appreciate everyones input to my issue. If anyone could possibly post a photo I what I should have, I can run out and get what I need to do it properly.
Thanks!
Mike

Inspektor Ludwig · Nov 15, 2009

You can install the waste tie-in on the horizontal like the last picture you showed but the fitting needs to be a wye and 1/8 bend or a combo and not a santee, which is what you have. Install the wye then you'll need to install another wye or combo (2") on it's back for the vent. Then you can add your 2" trap with an 18"-min to 30" max. standpipe. You'll need to tie your vent into another vent at least 6" above the top of the standpipe and with a vent from a fixture on the same floor level or you'll need to locate a vent upstairs and tie into that vent but you need to be 6" above the flood level rim of the fixture vent that you're tying into. Use purple primer and chamfer all the edges of the pipe.

Export! · Nov 16, 2009

I'm just learning but isn't that 3" TEE in the left of the picture a violation as well??

Rich B · Nov 16, 2009

export! said:
I'm just learning but isn't that 3" TEE in the left of the picture a violation as well??

Yes it is from what I read in my book. Apparently lots of them are out there. My house has one where the main stack turns horizontal. 4" C.I. done in the 1950's

Doherty Plumbing · Nov 16, 2009

Rich B said:
Yes it is from what I read in my book. Apparently lots of them are out there. My house has one where the main stack turns horizontal. 4" C.I. done in the 1950's

That's what we up here call a "tee on it's back". Never allowed basically and is bad piping practice as well.

You shouldn't ever use a tee to go from vertical to horizontal, only horizontal to vertical.

Washing machine drain question

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