Flange in slab not level

[C6H12O6]

I'm new, so please forgive the newbie question. I've been reading the old threads for a while, but can't find exactly what I'm struggling with.

As you can see in the pics, I have removed the toilet from my concrete slab floor. The back of the PVC flange is about 3/8" lower than the front. It appears that the flange was in place before the concrete was poured, so there really isn't anything underneath supporting the flange. It sits pretty snug, but the old toilet was leaking slowly for a long time before it was replaced. The front of the flange is about level with the concrete.

Under the flange, the waste pipe (3") only goes down a few inches before it turns 90° to the back wall. Please tell me I don't need to chisel out the concrete and replace the flange. Is there anything that will fix this alignment issue and secure the flange properly?

Our other bathroom had a similar problem. I wasn't too worried back then and replaced the toilet and used a thicker wax ring. No leaking so far — it's been a little over a year, however, I've spent way to much time and money on this second project to be pulling it all up again in another few years. I want to make it right but money for a plumber is long gone.

Help me Obi-wan.

 

[Gary Swart]

Well, the right thing to do is to break out concrete and install a new flange, making sure it is set level on top of the finished floor and anchored to the slab which should be filled in so it is very close to the drain pipe. What you have now is slightly recessed in the floor as well as not being level, and it is not anchored to the slab so you really have 3 problems. The only thing you can do with the existing flange is to use the thicker wax ring and shim the back of the toilet to level. This may or may not be a lasting solution. The out of level flange was likely the main reason for the old toilet's leak, but the flange not being securely anchor could have been part of it also. You might be right back where you started if you don't replace the flange. Actually breaking out concrete isn't really as difficult as you may think. You can rent a small electric hammer-drill that will make it fairly simple. Since you are working with PVC, the actual plumbing should not be too difficult, and some Quick Crete will take care of the concrete replacement. Since the concrete work will be under the toilet, it does not have to have a perfect finish. Having said all of that, it would be best to hire a plumber to do the flange. He can tell you how much concrete to remove so you can save some money on that part of the job. I'd hate paying a plumber his hourly rate to do such a non technical job! The long and short of my advice is that this is not a good place to cut corners to save a few dollars.

 

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[C6H12O6]

!@#$

Since I'm new to the board and I don't really know the rules regarding swearing in a post, I'll abstain. However, know that I am cussing up a storm in my head.

I was really hoping the answer was, "Oh, yeah. We see that all the time. Just go pick one of these up at Home Depot. You'll be fine."

I don't think I'll need to remove too much concrete. It doesn't look like there is any under the flange at all. In fact, in both bathrooms (I guess I need to do BOTH toilets ~ super) there were roots growing up around the edge of the flange between the plastic and the concrete. Nothing major, but very fine, lacy roots coming through and out in between the layers of linoleum. What a PITA. I'd really like to avoid having a plumber out twice to fix this. Is the old flange something I can remove with a dremel and some patience, or do I need to have the plumber out to remove it, then come back to put the new one on?

 

[C6H12O6]

Ok, as I'm thinking about the mountain of work before me, I have a couple new questions:

1. If the flange is tilted like it is because the whole pipe system it is attached to is tilted, how does adding a new flange fix that? Won't the new flange be tilted, too? I guess I don't see how I can change the angle by adding a new flange to a tilted vertical pipe.

2. How do I get the old flange off? I could cut it all off below the flange, but that will leave me with a too-short vertical pipe (stack?). As I think about how that would go, perhaps that is why I need to break some of the concrete out of there to give me room to add another vertical section.

3. If I do end up adding another section of black ABS, how close do I want to get with the new concrete to the pipe to allow me (or a plumber) to add the new flange when it's time for that?

 

[Gary Swart]

This is going to sound like a smart a..ed answer to your serious questions, but those are the things that plumbers know how to do and why they get paid a pretty good price for doing it.

 

[C6H12O6]

Not really smart a$$, just sort of a$$. I know I'm new, but I was under the impression this is a "Plumbing & Remodel DIY advice forum." If you don't want to help any further, fine. You obviously know what you are talking about and I appreciate your earlier help, but I really doubt most people on this forum come to a DIY forum looking for, "call a plumber."

 

[Gary Swart]

No, most don't come here looking for that answer, but when a person is asking for assistance on something that is obviously beyond his ability and training, that is the best advise we can give. You apparently have the believe that a plumber is just a dumb slob that charges big money for jobs that anyone can do. I'm sorry I offended you. You are certainly free to take or leave any or all advise and suggestions you get on this forum.

 

[C6H12O6]

He can tell you how much concrete to remove so you can save some money on that part of the job. I'd hate paying a plumber his hourly rate to do such a non technical job!

I never claimed to have the training or skills of a plumber. As for my ability level, you have no idea what my abilities are. I know my questions are remedial for an expert, but I thought that was what a forum like this was for – the DIY guy/girl who needs a little guidance to do a project on their own. If parts of this project are beyond my ability level, fine. That's honestly what I was trying to ascertain by asking my questions. If I would have gotten honest answers instead of, "call a plumber," I would at least know what to ask and how to listen to the plumber I do end up working with.

I do value the skills and expertise of tradesmen like plumbers, but that doesn't mean I have the money to pay one of them to turnkey this project. Like you said earlier, I too would hate to pay a plumber to chip away at concrete for a few hours when I can do that myself.

 

[Jadnashua]

Once you get the existing pipe uncovered, you can better asses what you have and what is needed to get it right.

They do make a special bit that is designed to ream out a fitting, so you might be able to cut off, then ream out the elbow, install a new vertical so you can then install a new flange. Depending on how far back you go, you might just replace the elbow, then you could get the thing vertical. You might find that once you free things up, it springs itself back to vertical - it might have been pushed over when they poured the slab.

When you fill the hole back in make sure the thing is level and plumb.

If the toilet has been leaking over time, roots will have found the hole. Three's probably something you can put in the hole to help suppress their growth before you put the concrete back in.

 

[C6H12O6]

Thanks, Jim. The flange is attached to the outside of and directly to the 90° elbow. If I cut the flange off, it seems that I'll probably bugger up the elbow. Even if I don't, I think I'd have to add some kind of vertical pipe above the elbow to give me enough height to mount the flange after the concrete fixed and the floor is done. That's likely going to be the plumber's job. I'm really just hoping to figure out how to get the old flange off and prep the concrete so I can finish the floor, call a plumber and get this project done.