I have a split level with a 1/2 bath on the slab floor and want to add a shower and drain for a washer. I'm comfortable with cutting the concrete and doing some digging, I just need to know how to plumb it. The main leaves the house about 6 ft. from where I would like to put the shower. The new washer drain would be on the back side of the shower. In between the shower and the main is a toilet. Can I tie into the toilet drain or do I need to go back to the main? Do I need to add vents? Where? I thank you for any advice you can give.

I have a split level with a 1/2 bath on the slab floor and want to add a shower and drain for a washer. I'm comfortable with cutting the concrete and doing some digging, i just need to know how to plumb it. The main leaves the house about 6 ft. from where i would like to put the shower. The new washer drain would be on the back side of the shower. In between the shower and the main is a toilet. Can i tie into the toilet drain or do i need to go back to the main? Do i need to add vents? Where? I thank you for any advice you can give.

Hi Brent,
Please excuse the delay. I was off for a day at the doctors and we experienced a high volume of questions. I'm still attempting to work my way out of them. As for your question.
If you could tie the shower into the lavatory drain it would be wet vented by it and wouldn't need a dedicated vent. However if you tied to the toilet or the main drain the shower would have to be vented separately.
The washer should tie in with the main drain and have ts own vent. To install the washer on the shower vent in hopes saving a vent wouldn't work because of the force and volume discharged by the washer. Because the shower will set just below the washer the discharge would come up out of the shower drain and then drain away. Not the best of good plumbing design.
However, you may tie the two vents together as a revent and tie back to a dry vent if you don't wish to take then out the roof. Good luck, Tom

I have a split level with a 1/2 bath on the slab floor and want to add a shower and drain for a washer. I'm comfortable with cutting the concrete and doing some digging, i just need to know how to plumb it. The main leaves the house about 6 ft. from where i would like to put the shower. The new washer drain would be on the back side of the shower. In between the shower and the main is a toilet. Can i tie into the toilet drain or do i need to go back to the main? Do i need to add vents? Where? I thank you for any advice you can give.
Tom,
Thanks for the advice, I haven't started the project yet and probably won't in the next few weeks so I'm in no hurry. I have one variation that I would like you to consider. Would I still need a separate drain from the main for the washer if I continued the 3" from the toilet to the washer and just T the shower into it? I would still need the vent for the shower but I wouldn't have to run two drains, but most importantly, I wouldn't have to tap into the main.

What I'm trying to do is to isolate the washer dischage from the lowest point in the drainage system, the shower drain. However, I'd fell a lot happier with the washer and shower on a 3" line then I would on a 2"drain line. F course both would need to be vented but the washers discharge would have a better shot at no backups on a 3" line rather then a 2 one. Regards, om

Thanks tom, I'll give it a try.