Fitting to closet flange new construction

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dzander77

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What's best to use for elbow right below closet flange
I could use a 4" into a 3" . As the pipe down stream will be 3" or just use a 3" closet flange and 3" elbo?
Any advantage of one over the other?
 
Best to use a 4 X 3.
3 X 3 will work.
Even though the toilet is bolted to both, the target into a 4" is bigger and therefore more efficient in allowing the toilet to discharge it's payload better.
 
ok, thanks. Do you know what size hole i should drill thru sub floor for the 4x3 fitting? Also is it ok to run a stub of 4" from the closet flange and then the 4x3?
 
Good question. I have seen them as deep as 3 to 4 feet.
To be honest , I'm not sure on the maximum depth.
It does not have to turn horizontal at all, as long as it's vented properly.
hole size would be the OD of the flange hub you are installing. YOU WANT TO MAKE SURE YOU HAVE solid wood under the flange to screw it down. not just plywood but wood under the plywood.
 
thanks for the info.
I could cut some pieces of 2x4 and screw them under the 3/4" subfloor the have the flange screws (stainless steel) screws down thru the subfloor and into the 2x4. Should really beef up that area. I could take a 2x12 and cut a ring like a donut. picture attached of one of the plumbed up toilets. I haven't glued anything up yet at this point. So i have 4" coming down into a 4x3 reducer, 3" on from there.

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Actually the vent should not be horizontal below the flood rim of the fixture it serves. The only time you reduce the size of the a drain in the direction of flow is is with a closet bend.

What you should do is use a 4x3 closet bend at the bottom of the 4" coming from the flange. The 3" will run horizontal to a 3X2 low heel outlet 90. The 2" on the low heel out will go straight up to the vent and the 3" will turn down to the main.

Then you HAVE to use a COMBO fitting to connect to the vertical main NOT a SANTEE

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Thanks very much for your help. I will change it as you recommend.
 
Is that 3" going into the 4" for the toilet
 
You can only use a 4" x 3" 90 on a toilet. That is the only time you can reduce in the direction of flow.
 
Actually the vent should not be horizontal below the flood rim of the fixture it serves. The only time you reduce the size of the a drain in the direction of flow is with a closet bend.

You can't reduce pipe sizes for draining.

You can only use a 4" x 3" 90 on a toilet. That is the only time you can reduce in the direction of flow.

Thanks for the clarification. That's kind of, sort of what I said. ;)
 
Ok
So 3rd toilet and vanity sink drain and vent.
4" pipe down from closet flange, 4x3 closet elbow.
3"x2" wye rolled over on 45 degree angle with 2" pipe up thru floor / wall to ceiling vent. 3"x2" I guess call it a double sanitary tee. One 2" going over and up to vanity drain. The other 2" will go to opposite side to shower drain. Not plumbed yet , as I don't have the drain rough in dimension yet. From double sanitary tee I continue on and drop down to 4x3 wye out to septic. Are there any mistakes or better ways to run this ?
also do I need a vent on the shower drain as I have the vent on the 3x2 wye right before the double sanitary tee?

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NICE

Almost perfect.

Change the double santee to a double combo or a double wye tee.
Better yet use two 3X2 wyes and stagger them.

You use a double santee on a vertical only. But the can cause problems when try to snake out a stoppage. Cable can pass through, rather than turning into the direction of flow.

A double fixture tee is not the same as a double combo or a santee.
It has a bit more sweep than a double santee which but can be used for back to back sinks

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Does this look good for venting of shower drain?
2" wye in drain line up and into same vent line as toilet
Thanks

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You want to prevent stoppages from fouling a vent.

The vent for toilet was good. NOW Not so good.

Run a second vent up into wall and connect to toilet vent above flood rim of toilet.
Why the long 2" horizontal run? wye not connect them to vertical below the low heel outlet on 3" with a 3 X 2 wye?

:confused::confused: That horizontal from the wter closet was going to the left and now at bottom of photo looks like something now going to the right.:confused:
 
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