View Full Version : unsupported toilet flange

12-28-2004, 06:59 PM
I started puting down new ceramic tile in an existing bathroom yesterday. When I removed the toilet I saw a bad problem. The hole in the concrete slab is larger than the toilet flange. The flange does not sit on the cocrete slab at all. I grabbed the plastic flange, and the entire flange pulled out of the pipe below. You can actually see the dirt at the bottom of the concrete slab and the vapor barrier that was cut off near the pipe. I have searched a lot of forums and posts and not come across this problem. I am thinking of inserting the flange connection and filling the void with a quick set cement. Being carefull to slide the flange bolts in the wet mix until it sets, so i can adjust them later. I would love to hear any other opinions, or from someone who has run into this before. Thanks a lot.

12-28-2004, 10:37 PM
The flange is supposed to be attached to the drain line! and solidly to the floor. What kept the toilet in place beforehand? Maybe it was caulked to the floor?

Does the pipe in the floor move at all? Is it plastic or cast iron?

Ideally, the flange should sit on top of the finished flooring. Depending on the pipe and the flange type, and if it moves vertically at all, you may be able to put the flange on the pipe after you get the tile down. One of the pros may have some other thoughts.

Is the flange one that fits on the outside of the pipe, or on the inside?

12-28-2004, 10:57 PM
The pipe on the flange fits inside the waste pipe under the slab. Both are PVC. There are no anchors connecting the flange to the concrete slab. Originaly, the toilet sat rock solid on the concrete slab. I guess the original plumber just tightened the bolts and sucked the flange and wax ring up against the bottom of the toilet to keep it from leaking. When in place, the flange is very hard to pull out of the waste pipe, and does not move. Unless someone has better advise, I am planning on filling around the flange with quick set cement and then bringing it up to finished floor by putting a leveling grout under the flange. I'm running out of time for this project. I really need to do something with this by tommorrow morning. I've taken to much time off work already. I thought putting ceramic tile on the floor would be an easy job. But we all know how that turns out, always something unexpected.

Thanks for any help guys.

12-29-2004, 04:05 AM
You should remove the flange, fill in around the waste/drain line with the quickset. When that has dried and after you have laid your tile, reinsert the flange into the drain line using PVC primer and cement. It dries almost instantly so you'll have to work fast. Then you should anchor the flange to the finished floor. You'll need a masonary bit and concrete anchors to snug it firmly to the floor. That's how to get this done correctly and it's not as catastrophic as it seems. Good luck!

12-29-2004, 03:32 PM
Sounds like the best thing to do. Is it absolutely necessary to cement the pvc flange to the pvc waste pipe. I'm kinda scared the flange might break off or something one day and I wouldn't be able to replace it.

12-29-2004, 03:41 PM
Well, it worked as it is, but it would not pass inspection or meet the building codes. If it breaks, and that is rare, you'd have a little more work to fix it. Usually, the bigger problem is if it leaks and rusts out. By not gluing it properly, thatis much more likely to happen.

My unprofessinal opinon...

12-29-2004, 04:02 PM
Thanks for all the advise guys. I'll let you know how it works out in the next day or two.

12-30-2004, 04:47 AM

You definitely should use the cement. I have in the past had to remove a flange that had been cemented to the line and, while time consuming and a major pain, it can be done. As previously noted, the flange shouldn't break. I suppose it could happen if you overtightened the bolts but if that worries you, use one of the flanges with the red metal ring around it. I believe someone (Terry???) posted a picture of one in an earlier reply to you.

Again, good luck.

12-30-2004, 04:21 PM
I grouted in with the quick set cement around the wast pipe. I then inserted the flange piece and continued grouting up to finished floor. During the procees, I would wiggle the flange a little so that i would be able to get it out later. You guessed it, the flange broke off. Even worse, I guess the liquid in the cement seeped between the two pvc pieces and glued them together. After a lot of work and cutting with a dremel tool, I finally got it out. I reshaped the cement by hand so that I can get a new flange connection in. This time, I think I'll insert the new flange to the proper height and pack under it with a floor leveling compound like Jasco floor patch. I only have to put about a quater inch under the new flange.

My new question is, would I be better off getting a metal flange for the new installation?

Thanks again guys. I'm getting there.

12-30-2004, 05:15 PM
Don't worry about taking it out again later. Done right, it will last decades and you'll probably not be there. Stop wiggling and glue it in place like it is supposed to be! Ideally, the tile would go UNDER the edge of the flange, and support it properly - the toilet flange is supposed to sit on top of the finished floor. You can get by if it isn't too far below the top, but it is really supposed to be on the top by design. A can of pvc primer and glue and a new flange can all be had for about $10 or so. If you get one with a metal edge, it is a little stronger than an all plastic one, but maybe not thatmuch.

12-31-2004, 05:19 AM
Since you're putting in tile and shouldn't reinstall the toilet until the tile is down, put the tile down first and install it around the waste pipe and then install the flange to the pipe last because the flange should sit directly on top of the tile (or whatever your final floor covering is).