Moving a toilet, need to plumb it

[John Gayewski]

I would just call this opinion of the offset flange, just that, an opinion. It's shared by many in my area, but they do get used.

 

[Reach4]

https://www.lowes.com/pd/Oatey-3-4-...t-Flange-with-Stainless-Steel-Ring/1000720810 says UPC listed

Push-tite offset 4 inch shows UPC listed. https://shop.hughessupplyftcollins.com/P3354671-SIOUX-CHIEF-889-GPOM-4-FULL-FLUSH-PVC-OFFSET-CLOSE

I expect it is the same with the ABS versions. For Push-Tite is OK to mix PVC and ABS.

 

[Sponsor]

 

[Jeff H Young]

Ah, for the UPC the applicable section would I believe be 310.5, excerpted below. Whether an offset flange complies with it is a great question.

Thanks,
Wayne

Chapter 3 General Regulations: General Regulations, California Plumbing Code 2019 | UpCodes

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310.5 Obstruction of Flow

No fitting, fixture and piping connection, appliance, device, or method of installation that obstructs or retards the flow of water, wastes, sewage, or air in the drainage or venting systems, in an amount exceeding the normal frictional resistance to flow, shall be used unless it is indicated as acceptable in this code or is approved in accordance with Section 301.2 of this code. The enlargement of a 3 inch (80 mm) closet bend or stub to 4 inches (100 mm) shall not be considered an obstruction.

Yep I think thats it Wayne 310.5 ! So Ill let you in on something as far as I remember we never displayed the offset to be scrutinized.
I still think the 45 degree flange may comply but not certain. never used one

 

[Zelbrew]

I guess I should have noted that the main waste pipe is 3".

I bought a 3" flange and a 45 flange to visualize. It looks like if I use the 3" with a 10" rough in toilet, I'll still be hitting the edge of the joist. Then the fitting on the flange would be wider. (I assume nobody likes a flange that goes inside a 3" pipe.) I think 10" rough in with the 45 or the offset is going to be the least amount of hacking. The 45 looks like it would start curving away from the joist by time you get through the two layers of subfloor and tile. Unless I am just totally missing something

 

[Reach4]

Inside 3-inch flange can be good, but there is less potential for mounting the toilet off center.

is a long tail 3-inch inside flange that is good. Sioux Chief 888-PM.

is inside PushTite. While it has a plastic ring, it could be replaced since it is not glued.

In the same category, https://www.oatey.com/products/oatey-twistnset-replacement-closet-flange-1098867162?upc=038753436548 there is the Oatey Twist-N-Set Closet Flange

 

[Zelbrew]

I was kind of thinking that I might use one of those temporarily until the final floor is finished. However, I don't think it solves the problem of the joist being in the way. It looks like even with a 10 inch offset I will still hit the joist with the pipe. It is kind of hard to tell right now because my understanding of where the joist is is based on exploratory holes drilled into the floor to find the joist.

If I can get 3" pipe straight up the side of that joist, I could trim away part of the top of the joist to make room for an outside flange and be well within the rules for notching. Could sister on the other side of the joist for good measure if there is a question.

In any case, I thought the consensus was that reducing a 3" pipe down further by inserting one of these flanges was a bad idea.

 

[John Gayewski]

I was kind of thinking that I might use one of those temporarily until the final floor is finished. However, I don't think it solves the problem of the joist being in the way. It looks like even with a 10 inch offset I will still hit the joist with the pipe. It is kind of hard to tell right now because my understanding of where the joist is is based on exploratory holes drilled into the floor to find the joist.

If I can get 3" pipe straight up the side of that joist, I could trim away part of the top of the joist to make room for an outside flange and be well within the rules for notching. Could sister on the other side of the joist for good measure if there is a question.

In any case, I thought the consensus was that reducing a 3" pipe down further by inserting one of these flanges was a bad idea.

Lots of people do it. I personally avoid it, but I can't say I wouldn't do it because sometimes to gotra do what you gotta do.

 

[Terry]

In any case, I thought the consensus was that reducing a 3" pipe down further by inserting one of these flanges was a bad idea.

Most new toilets have a 2" trapway, dropping into a 3"
The bend below is going to be 3", so I don't see a problem with the inside pipe closet flange on the vertical.

 

[Zelbrew]

Most new toilets have a 2" trapway, dropping into a 3"
The bend below is going to be 3", so I don't see a problem with the inside pipe closet flange on the vertical.

Ah, OK, good to know.

So, in your opinion, if I have clearance to get a 3" vertical next the joist, would it be better to use an inside flange than to use an offset (which would fit outside the vertical pipe)? The inside flange would save me from having to greatly alter the plumbing later when I raise the floor.

BTW, referring to questions earlier about the offsets, I think they all claim to be able to pass a 3" sphere.

 

[Zelbrew]

Ah, OK, good to know.

So, in your opinion, if I have clearance to get a 3" vertical next the joist, would it be better to use an inside flange than to use an offset (which would fit outside the vertical pipe)? The inside flange would save me from having to greatly alter the plumbing later when I raise the floor.

BTW, referring to questions earlier about the offsets, I think they all claim to be able to pass a 3" sphere.

The question of whether I can get the pipe next to the joist relates back to one of my early questions about how much wiggle room is there with the rough in measurement.

 

[Jeff H Young]

The question of whether I can get the pipe next to the joist relates back to one of my early questions about how much wiggle room is there with the rough in measurement.

depends on the toilet obviously more than 12 inches off the wall isnt a problem if you dont mind the gap. Id say about 11 inch minimum is really pushing it the bolts can be cheated a little. take wall out behind toilet and run the studs flat will give you 2 inches? possible. they say you gotta crack a few eggs to make an omlete this cant be that hard there is a solution.

 

[Reach4]

The question of whether I can get the pipe next to the joist relates back to one of my early questions about how much wiggle room is there with the rough in measurement.

Hard to say. Would 9.5 work? Easy. Would 9.0? Maybe. If you need 8.25 rough, then I am confident that is not going to work. Rear exit toilet? Probably not, but see what you can see.

Measuring accurately is called for. Drilling a vertical 1/8 hole on both sides of the joist would make nice measuring references. Drilling from below ensures the drill does not come down into the joist. A drill bit extension can be nice to help the drill clear the joist.

 

[Zelbrew]

Hard to say. Would 9.5 work? Easy. Would 9.0? Maybe. If you need 8.25 rough, then I am confident that is not going to work. Rear exit toilet? Probably not, but see what you can see.

Measuring accurately is called for. Drilling a vertical 1/8 hole on both sides of the joist would make nice measuring references. Drilling from below ensures the drill does not come down into the joist. A drill bit extension can be nice to help the drill clear the joist.

I think I'm pretty close with the exploratory holes I drilled from the top, but I may crawl in there with the snake skins and do a more precise job.

 

[Reach4]

Stick wires down your holes so that you can easily find them from below.

Take measuring tool and notepad plus pen.

 

[Zelbrew]

So placement of the flange aside, what about the rest of the plumbing? Is it just a matter of 45 over to above the soil pipe and then dropping vertically into a fitting? I know that 45 and steeper is considered vertical, so basically it is going to be vertical the whole way.

 

[Jeff H Young]

Don't know what code you have but don't forget the vent

 

[Zelbrew]

Still wondering about the plumbing to the main line, but I started thinking about venting. Can I vent off of the vertical once I get below the floor joists? And related: I don't need to turn horizontal for this plumbing do I? Is vertical OK all the way, with venting with a wye {or similar}?

 

[Reach4]

Still wondering about the plumbing to the main line, but I started thinking about venting. Can I vent off of the vertical once I get below the floor joists? And related: I don't need to turn horizontal for this plumbing do I? Is vertical OK all the way, with venting with a wye {or similar}?

Under IPC, you can vent a toilet pretty much any place before it joins non-bathroom waste. Usually this is done by joining a vented bathroom fixture's drainage (wet venting, often the lavatory provides the venting) before joining non-bathroom waste.

 

[Zelbrew]

Under IPC, you can vent a toilet pretty much any place before it joins non-bathroom waste. Usually this is done by joining a vented bathroom fixture's drainage (wet venting, often the lavatory provides the venting) before joining non-bathroom waste.

OK, so if I can get my rough-in location and drop straight down, I can use a wye from the vertical pipe and run the vent up the wall and tie into the vent system in the attic? There is a sink close by, but running to it to wet vent would be near impossible. We are not gutting; most drywall is staying intact except to add the vent up the wall behind the toilet.

 

[Reach4]

What you propose is very good. I am not sure what the minimum size of that dry vent is, but without looking it up I know it is not more than 2 inch. If you were considering 1.5 inch, then that should be checked.