Hello,

A quick question about my basement bathroom project. I have exposed my 4" main. If you are looking at the main from above it runs from right to left draining to the left. The farthest left fixture will be the toilet which I am dropping down, then using a 90 bend and tieing into the main with a Wye and that shoots on out to the left. The run from the 90 degree to the Wye will only be a matter of 6 inches or so.
The next fixture moving to the right of the main will be a the shower line which is only about a foot to the right on the main line and is connected by a Combo tilted up at a 45 degrees....this will lead to the shower which is only 2 or three feet away and has a vent in between the shower trap and the main. (all lines are 2" except the main and the toilet which are 4") THIS IS MY MAIN QUESTION. Will this vent that is on the two inch line that runs to the shower be sufficient to vent the toilet which is on the main line but only about 2-3 feet away? In theory in works because the major fixture (toilet) is downstream of everything and there is a vent between the toilet and the shower on the 2" shower line.

Finally, a little more to the right on the main line I have another Combo which has by lavatory line which of course is vented and eventually ties back into the shower vent in the walls and out the roof.

Basically, I am not sure what my critical distance is for the toilet which is basically connected directly to the 4 inch main and moving upstream I have that 2" branch line tilted at a 45' with a vent and the shower trap on that line. I am hoping that vent will be sufficient to vent the toilet which is the furthest fixture downstream. (keeping in mind the toilet is only 3 or so feet from the vent.

Summary:
Question 1: Will that vent for the shower line work as a wet vent for the toilet downstream?

Question 2: The Wye that connects the very short run from the 90' toilet bend. Does that Wye need to be angled up at all? Or can it just sit level with the main line (which of course is graded at 1/4 inch per foot)

Thank you for your time.

I'm a little confused. Are you informing me what you already have or are you asking me if it will be in code if you install it the way described? If it's already in place the answer will be:
Question 1: Will that vent for the shower line work as a wet vent for the toilet downstream? Yes It will be vented
Question 2: The Wye that connects the very short run from the 90' toilet bend. Does that Wye need to be angled up at all? Or can it just sit level with the main line (which of course is graded at 1/4 inch per foot) ? Since the distance the discharge has to go before entering the main the velocity generated by the drop to the closet bend will be more then enough to insure the toilet has drainage. In short, it may have zero fall.

Now if you're getting ready to install the job I may come up with suggestions that will allow you to use only one vent, (the lavatory vent) for the entire bathroom group and do away from reventing the shower vent. Let me know. Regards, Tom

I have not yet begun construction. Any advice on how to share one common vent for entire bathroom group would be great. Here is a rudimentary drawing of bath layout.. keep in mind it's a small bath.

... Shower
..
..
... Vent------!
..
..
----------------------------------------------------------
<----4" Main
----------------------------------------------------------
... \..
... Toilet... line to Sink and vent

Any way to vent all three with one vent would be great. Though it doesn't seem like too much trouble to run a second vent from the shower up into the wall and just have them meet up and head up to the roof. But any advice would be great! Thank you for your speedy first response.

Quote:

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Originally Posted by rthies99

I have not yet begun construction. Any advice on how to share one common vent for entire bathroom group would be great. Here is a rudimentary drawing of bath layout..keep in mind it's a small bath.

.....................Shower
..........................!
..........................!
...........Vent------!
..........................!
..........................!
----------------------------------------------------------
<----4" Main
----------------------------------------------------------
..........\..................................!
........Toilet...................line to Sink and vent

Any way to vent all three with one vent would be great. Though it doesn't seem like too much trouble to run a second vent from the shower up into the wall and just have them meet up and head up to the roof. But any advice would be great! Thank you for your speedy first response.

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If your fixtures were all on the same side of the main you could have drained the shower into the lavatory drain where it would wet vented by the lav vent. However since you would have to jump across the main to do it your layout works best for me. Good luck, Tom

Thanks for your advice Speedball... I've done PVC work in the past... and have noticed it's somewhat difficult to dry-fit the pieces... as sometimes they are extremely tight and you can't get them squeezed all the way together. Then when you go to cement it... you get the parts completely squeezed together because of the lubricating factor of the glue... and things don't fit exactly as they did during the dryfitting phase... any advice?

Quote:

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Originally Posted by rthies99

Thanks for your advice Speedball....I've done PVC work in the past.....and have noticed it's somewhat difficult to dry-fit the pieces....as sometimes they are extremely tight and you can't get them squeezed all the way together. Then when you go to cement it.....you get the parts completely squeezed together because of the lubricating factor of the glue.....and things don't fit exactly as they did during the dryfitting phase...any advice?

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The problem with "dryfitting" PVC fittings is that if you push them tight they are extremely difficult to pull apart when you want to prime and glue them and if you don't push them together you can't get a accurate measurement.
The reason for this is that the female side of the hub has a slight taper that almost locks the two when shoved together without the lubricating application of the glue.
Some of us get around this by laying the PVC fittings next to each other and getting a measure that way while some of us push the fittings together until they start to bind up and measure the distance between the male section and where it would butt up with the hub. We can then subtract the added measures and get a fairly accurate overall measure. There are drawbacks as well as advantages to working with plastic but the advantages far outweigh the drawbacks. Good luck, Tom

Spoke with a coworker's husband who is a licensed plumber. I showed him my diagram and he said that venting on the opposite side of the main would not work in this situation. He said because this main waste line is in the basement it theoretically could be filled with flow from upstairs when I flushed the basement toilet... therefor it would not be able to properly vent from the other side of the main... he said I would have to vent it on the side the toilet is on... that little branch... thoughts?