Newbie Question: Toilet Install

**DerekW** · 01-19-2008, 05:31 AM

Hello Everyone,

I have a very basic question about the right flange for a toilet install.

I am working on finishing a master bath and am about to put down underlayment and ceramic tile on the floor. The existing rough waste pipe (PVC) I need to connect to is 4" outside diameter, (3" Santee) and the inside is flared out on the end, seemingly to accept a pipe fitting inside it (see pic #1). I bought a PVC flange...a 4'' spigot flange...that fits over the outside of the rough pipe (pic #2). However, the top of the rough pipe sits approx. 1 1/4" below the surface of the subfloor, and the extension on the flange is approx. 1 3/4", giving only about 1/2" of overlap over the rough pipe.

So my newbie questions are:
1) is 1/2" enough of an overlap for the connection?
2) is it OK to have a flange that goes over the outside of the rough pipe, or should I get one that fits inside of it?
3) should I prime & cement the connection like any other PVC connection?

PS: (I am putting down a underlayment layer of 3/8" plywood, but I can put the flange directly on the sub-floor and cut the underlayment around it if I have to)

Thanks...really appreciate your help!

Derek

**Cass** · 01-19-2008, 05:41 AM

The fitting in the pic sure looks looks like a T to me and is not the right fitting for the job, it needs to be removed and changed. It needs to be a Y and there needs to be a vent somewhere.

Also the sub floor appears to be cut to wide, maybe I'm wrong, as it needs to go under the flange when it is installed so that the flange can be screwed into it.

**DerekW** · 01-19-2008, 06:58 AM

Cass, thank you.

The picture may not be the best. I believe the rough pipe is a "Y" not a "T" (hard to tell in the pic). The rough plumbing has been in a number of years but passed a plumbing inspection when the house was built.

The cut-out is a little large as you observed, but the flange can still be screwed in over it OK.

Assuming this is all OK, can you help with my other questions?

Thank you!

Derek

**jimbo** · 01-19-2008, 07:46 AM

It does not look like a wye, but ......

You will not find a flange which would go on the outside of that hub, but putting it inside is fine.

Ideally, the flange should rest on top of the finished floor.....including tile,etc. If you put it lower than that, you will need to use one or more 1/4" thick flange extensions to get it to the right height to seal the wax ring.

Would love to see a "sideways" pic of that fitting in the floor. Looks like a vent tee, might be a san tee, but I can't see a wye there.

**patrick88** · 01-19-2008, 08:19 AM

That looks like a tee wye. You need to replace it with a wye. It may have passed inspection, but The plumber might have been friends with the inspector. What everybody else said you need to put the floor in before the flange.

**Gary Swart** · 01-19-2008, 08:59 AM

We always are looking for the quick and easy way out of problems aren't we. I don't mean this to be critical of you, it's a basic human characteristic. What I would consider doing here is to remove the sheet of plywood subfloor to gain good access to the fitting. Replace the fitting as needed, making sure it is vented properly, the replace the subfloor with a new piece of plywood that was cut with a smaller hole. I would not attach the flange until after the finished floor was done so it would be set on top of the finished floor as it should be. This should be a once-in-a-lifetime job, so spend a bit of time and a small amount of money to get it right.

**DerekW** · 01-19-2008, 10:03 AM

Jimbo, Patrick, Gary,

Thanks for your responses. Sorry guys, I'm a newb and don't know what vent Ts, san Ts, and tee wyes are, so I can't confirm that's what I have or not. The reason I said I thought it might be a "Y" was that there is a slope on one side of the fixture going in to the horizontal pipe under the floor...looks like it would give the water/waste a little push in the right direction as it flowed into the horizontal pipe . But I'm not a plumber...that's why I'm here for help!

Also, I'm not trying to avoid a correct solution at all. I'm just surprised to hear that what's in there (done by a licensed plumber) has to be replaced. I was writing with a different/simpler question, assuming what was there was good!

But, if as you say what's there is trash, I will replace it. If I can get a better angle on the pipe for a better pic I will do so and ping back to you. If I can't, and with your help, I can't confirm what I really have there, I'll call a local plumber (not the one who put it in) and see what he says.

Thanks again...if anyone has any other insights or advice in the meantime I'd love to hear it.

Regards,

Derek

**jimbo** · 01-19-2008, 11:39 AM

I don't think we will suggest tearing out what's there. It was installed, presumably by competent person. It will probably work fine. Our questions/comments stem from out tendency to be overly nitpicky sometimes! Sort of a contest!

You can look at this catalog to see the difference between the various tees and wyes. These differences are important from a code standpoint, so we always talk about it.
http://nibco.com/assets/PDWV0108.pdf

**DerekW** · 01-19-2008, 11:45 AM

Not to beat this to death but Patrick, if you're still out there I might have the "tee wye" you suggested.

There is a "coupling" under where the toilet will go, into which the ends of the horizontal waste pipe is connected. I suspect this is called a tee. Off of that coupling comes the pipe into which the toilet will drain. It comes off the coupling at an angle, like a Y. So this may be the "tee wye" you suggested.

I will call a plumber to confirm and replace as everyone has suggested. Just for my own education however, what's the difference between a "wye" and a "tee wye", and why is a "wye" OK and a "tee wye" not? Just trying to understand.

Thanks everyone for your help!

Derek

San tee

Combo or can be made up with a wye and a 45

The tee can't be used on it's back for waste.
A combo fitting can.

**DerekW** · 01-19-2008, 02:15 PM

Terry & Jimbo,

Thanks for the schematics and the link to Nibco! After reviewing the pics and taking a ride to the local builders supply in town, I believe the mystery is solved!

But the bad news....I'm 99% sure it is a 3" sanitary (san?) tee.

It looks like it's made to have a section of 3" pipe connect it to the toilet flange.

The main shell of the house was built in 1997, (inc. most of the rough plumbing and about 1/2 of the rough electrical). The house is in Northwest Maine, and I don't have a clue what code was when the rough plumbing was done, but it was put in by a licensed plumber and passed inspection back then. My wife and I are now doing a lot of the finish-out ourselves...hence my questions and this thread.

I guess my question going forward would be: is the problem with using a sanitary tee due to some functional or design problem with this particular component (e.g., it does not pass waste/water thru efficiently and causes clogs?), or because it is out of favor from a code perspective...or both?!

If it passed code when it was put in (it did) and is still a functional plumbing component, I might be tempted go with it. But if you tell me it's a problem waiting to happen I'd be happy to follow your advice and rip it out.

Thanks in advance for all your help on such a basic issue!

Best Regards.......Derek

**Marlin336** · 01-19-2008, 02:23 PM

I would leave it. I see them installed on their back just like that all the time for toilets and it always passes inspection. THe ones I've seen are 4" cast iron though, I don't know if that makes a difference. If you use a wye you have to put a 45 on it to get it vertical and that might put you too high. A wye is better but a san tee should be fine.

**Terry** · 01-19-2008, 02:47 PM

I've seen some funky things in other states.

For many plumbers on this board, it doesn't look right
Normally, the closet bend is the last bend, and it all has to go one way.
With a tee on it's back, is the other side a vent, or does other waste come down the line?
A tee on it' back does not guide the "media" down the line, it can just drop there.
A wye fitting points it on it's way with a mighty shout and fury.

**cwhyu2** · 01-19-2008, 03:10 PM

That is what we would call a flat vent and is not allowed here.Terrys drawing
shows it best.

**Marlin336** · 01-19-2008, 09:49 PM

Originally Posted by Terry

I've seen some funky things in other states.

For many plumbers on this board, it doesn't look right
Normally, the closet bend is the last bend, and it all has to go one way.
With a tee on it's back, is the other side a vent, or does other waste come down the line?
A tee on it' back does not guide the "media" down the line, it can just drop there.
A wye fitting points it on it's way with a mighty shout and fury.

I'm not arguing that a wye isn't the ideal way to do it, it defiantly is. I'm just pointing out that he may be allowed to use that fitting, even if it's not allowed I wouldn't go doing a major re-model to remove it.