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Old 08-13-2011, 05:16 PM   #1
burchis
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Default Double vanity rough-in question.



Would this arrangement of a vent-tee work in stead of double sanitary tee? I plan on wet-venting from about 5 feet away.

Thanks for any help and/or comments.


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Old 08-13-2011, 08:17 PM   #2
Caduceus
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Wet venting isn't going to work in this situation. I also would recommend using a cross instead of the tee you have. Out of the top of the cross you can put a 90 ell coming out of the wall for a cleanout as long as it doesn't get blocked by drawers and is accessible. Better yet, if you can use a wye a bit lower on the vertical to go to one sink then a 90 on top of it to go to the other sink. Hope that makes sense.
As far as venting, the vent would have to be after the trap before you change from horizontal to vertical.
Is this a new construction house or a personal remodel project?



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Old 08-13-2011, 08:25 PM   #3
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Cad, since I am also preparing to convert a single basin to a double basin, could you draw out what you are describing?

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Old 08-13-2011, 08:31 PM   #4
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Havasu, I don't have the computer savvy to do that, but I am consulting my 'internet technical trainer', a.k.a The Wife, unless you can explain it.

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Old 08-13-2011, 08:34 PM   #5
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I neglected to mention that if a cross is used, a vent must be installed above it and continuing through the roof or AAVs used at each fixture after the vanity is installed.

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Old 08-13-2011, 09:23 PM   #6
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This is remodeling in 35 year old house. Basically I am just rearranging an old bathroom, where originally there wasn't any venting at all. I'm doing all the work myself and no county inspector will be involved.

Could you explain what problems I would have by using the vent-tee as shown in the photo? i.e- partial waste from one drain flowing into the other drain, etc.

Would a double-wye work as apposed to your suggestion of using a wye and 'L" combination?

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Old 08-13-2011, 09:44 PM   #7
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With that setup the traps on the sinks will siphon allowing sewer gas to enter the home. The other concern is when trying to snake the line from under either sink the snake would just run from one sink to the other without entering the common drain line. A double Y would make drain cleaning better but you still have the same problem with sewer gas. The correct way is with a double sanitary tee with a vent coming off the top. Just because there is no inspection doesn't make what your doing any less dangerous. Codes are written for a reason. Do yourself and your family a favor and do the job correctly.

John

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Old 08-13-2011, 10:57 PM   #8
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Echoing what the others have said, with a slight twist. I would use a single sanitary tee underneath another single sanitary tee, the second one being at the height that you currently have the drains at. Then, if necessary, use a slip extension to to attach the vanity bowl to the lower drain arm.

And make sure you vent the stack. The wet vent that you are trying to use is an S trap, disallowed by code for a reason.

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Old 08-14-2011, 02:06 AM   #9
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THERE IS NO VENT IN YOUR PICTURE... this is bad, you must install a vent.

IF you want to use this type f configuration you must install a double sanitary T not the bull headed t that you have there and at VERY MINIMUM install an air admitance valve on the to of it, with an access door to get to it.

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Old 08-14-2011, 02:33 AM   #10
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Can an AAV value be used on top of a double sanitary tee which would be closed off with drywall.



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