Ok, I asked once before, but I kind of changed things around a little bit and want to make sure I do things right before I start busting out concrete... where do I put the vent line or lines? This will all be under a concrete slab when I get done... there should be an attachment.

You will run a vent from the lavatory through the roof or revent back in the attic. This will wet vent the entire bathroom group. If you can, increase the lavatory drain to two inches. Good luck, Tom

THANKS! Would it be possible to vent from the shower line?

THANKS! would it be possible to vent from the shower line?
No! That would mean installing a "S" trap on the lavatory and that's not acceptable. Vent from the lavatory. Regards, tom

Thanks For Your Help!

Is the 1 1/2" line big enough? of should i go to 2"?

1.5" is "big enough" for the lavatory according to code...


BUT.

You're cutting up your concrete floor to put these in, and you don't want to have to do that ever again i assume.... So for the very small increase in cost of 2" versus 1.5" you can have a drain that's significantly larger (doesn't sound like a big increase but it is) any way, way less likely to become blocked, and one that will be easier to clean if it does become blocked.

Really, using the 2" is a no-brainer.

Also, I would install a nice cleanout Wye on the lavatory drain, in case you ever have to snake the drain. Of course, that's just me... paranoid. But is really, really IS cheaper and easier to do it right the first time and we're not talking about expensive fittings here. Your time is worth more than all of the PVC for the whole project.


~aaron


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Thanks! Everything else look a-ok to you? I guess it don't matter on the toilet which way you set the elbow coming of it does it?