Moving Toilet Flange

**Bobbletown** · 02-26-2013, 01:29 PM

Hello,

I'm doing a bathroom gut and have run into an issue that I've never tackled before. I've stripped the floor of its linoleum and 1/4" wonder board. I noticed that the 3/4" subfloor also needs to be replaced so I'm going to move forward with that. Here is my problem while I have the floor and piping accessible...

I'm going to change the layout of the bathroom which will require the toilet flange to be extended 19" from its current location. This extension will take place along the same floor joist (accessible from the basement). No 45's or 90's just a straight run. The run is about 12 feet of 3" copper and is properly slopped at 1/4" for every 4 feet.

I'm thinking of a copper to PVC union once the pipe is cut then attaching the closet flange once I install the new 3/4".

For you plumbing pros...How would you extend it? Are there any issues with a waste line if you have a union from copper to PVC? Meaning, will anything from that connection potentially "catch" solid waste since it's no longer a seamless run? Also, the new flange will be a 14" rough-in from the wall due to baseboard heaters, any issue with that other than the extra 2" behind the toilet? Thanks.

**jadnashua** · 02-26-2013, 03:38 PM

You could stick the toilet in the middle of the room, it can stand alone anywhere...might not look good, so moving a 12" toilet design and installing it on a 14" rough-in would be fine. Some wouldn't like the tank away from the wall, but it would work fine.

To transition from copper to PVC, you'd need to go to a plumbing supply house for the proper nohub connector. The big box stores tend to only carry those designed for pvc-pvc, or pvc-CI. The ID of both the 3" copper and the 3" pvc are the same, but the ODs are different. You need the proper nohub that takes the OD size difference into account. If you get that, there should be no 'step' in the pipe when properly joined.

Extending the pipe nearly 2' means nearly another 1/2" of rise. PVC fittings are often taller than copper ones, and depending on where the pipe is now, that extra rise may make it hard to get the required fittings in there.

**Bobbletown** · 02-26-2013, 04:37 PM

ok, thanks for the input. Luckily I do have a good plumbing supply store nearby so get the proper fittings won't be a problem.

**mtcummins** · 02-26-2013, 04:54 PM

1/4" for 4' of pipe is NOT proper pitch. Proper pitch is 1/4" per foot. If that's all you have, and there's a little room to work with, I'd suggest cutting out the rest of that 3" copper line and leave just enough to get your nohub connector attached, and rerun the whole thing with PVC at proper pitch.

Also, is this toilet vented? You can't have the toilet that far away from the stack w/o a vent. If its w/in 6' of stack you don't need a vent, any further and you do. Most code requires a 2" vent for a toilet arm.

Bonus: Cha-ching at the scrapyard! 3" copper pipe brings in a lot of money. Might pay for your project... Its always a good day when you're doing a piping replace on DWV that's copper...

**mtcummins** · 02-26-2013, 04:55 PM

Oh, and make sure you support that 3" every 4' along the horizontal, or you'll get a sag. And that's just a drag on a poo...

**Bobbletown** · 02-27-2013, 06:21 AM

Originally Posted by mtcummins

1/4" for 4' of pipe is NOT proper pitch. Proper pitch is 1/4" per foot. If that's all you have, and there's a little room to work with, I'd suggest cutting out the rest of that 3" copper line and leave just enough to get your nohub connector attached, and rerun the whole thing with PVC at proper pitch.

Also, is this toilet vented? You can't have the toilet that far away from the stack w/o a vent. If its w/in 6' of stack you don't need a vent, any further and you do. Most code requires a 2" vent for a toilet arm.

Bonus: Cha-ching at the scrapyard! 3" copper pipe brings in a lot of money. Might pay for your project... Its always a good day when you're doing a piping replace on DWV that's copper...

You are absolutely correct regarding the slope, 1/4 for every FOOT not every 4 feet! My bad, the J hooks are spaced every four feet. The stack is approximately 2 feet from the closet flange.

Someone brought up another potential issue with the extra 2" from the 14" rough-in.....if someone leans back it could potentially bend/break the bolts from tank to toilet. I was going to either shim the back of the tank or build out a decorative shelf since it's a rear wall the toilet rests against.

**mtcummins** · 02-27-2013, 08:25 AM

today's toilets are not supposed to actually touch the wall, so that's not really much of a concern. If you put in a 12" rough toilet, it will likely be 1/2" to 1" from the wall anyway.

that said, this makes me nervous too, and I often will put a small block on the wall behind the tank that just gives a little support in the event of a hard push on the tank. this isn't required though, you'd be fine w/o it.

**jadnashua** · 02-27-2013, 01:07 PM

A block behind the toilet (that is actually touching it) might create enough stress to crack the tank, not prevent it under certain circumstances...toilets are designed to be free-standing...don't worry about it unless aesthetically, you want to. But, if there is a radiator back there, blocking it off might create more problems. You might want to use something other than wax for the seal, but it would probably be okay.

**mtcummins** · 02-27-2013, 06:45 PM

Yeah, I don't have a block behind my Toto, as I was able to get the tank to seat securely down on the rim of the bowl with no wobble. My previous POS toilet didn't have a raised rim, and the tank would move all over the place if you pushed on it at all. This didn't sit well with me, so I put a small block behind the tank just to reduce movement. I know its not necessary, but it made me feel better about the thing.

Good point about the heater and the wax ring Jim. I have heated floors, and had to insulate the heat piping in a 2 foot radius around the toilet flanges to avoid this issue, but hadn't thought about it from a baseboard. Seems like it would most likely be ok, but might want to go with a waxless just to be safe.