Issues with Closet Flange on lead bend

[Tally Wacher]

Gentlemen,

I've been having issues with sewer gases emanating from a toilet. Some poking around found that the gases were coming from the bottom. The toilet is a Toto not sure what model but it is a 1.6l flush.

Removed the toilet and found that the flange is crooked and there is a gap in the back half of the flange to drain junction. The toilet functions ok and there are no leaks, just the sewer gas issue. There is a shelf in the drainage pipe. The gap between the flange and pipe is along this shelf. The front half of the connection between the flange and pipe is intact. Please see pics below. Sorry not sure why the profile shot of the flange is upside down, but you can see that it is not level.

My plan is to seal off the gap between the back half of the pipe/flange junction with 100% silicone caulk, dry fit the toilet and shim, and throw a thick wax ring on there. Please let me know what you think. Thanks.

 

[Reach4]

You are thinking of putting silicone under the outside edge of the high part of the flange. While you could do this, I think an acrylic caulk, such as you will use around the base of the toilet, would be good too. Less expense and potential mess.

If you use wax, you must not lift the toilet at all once it goes down. Thus you don't want to insert shims after the toilet is down. You can position the shims before, tape them in place in a hidden way, and then drop the toilet. Alternatively, you could use a waxless seal. Those can conform. However your idea of using wax may be best here.

For the wax, you could use a jumbo ring as it comes. But you can mold that by hand to the shape you want. I would do that. I would wear nitrile gloves to make hand cleaning easy, although the wax is safe to handle. Anyway, after shaping, I think the top of the ring you form can be pretty much uniformly sticking up maybe 7/8 or 1 inch or so above the floor. Then lower the toilet onto the shims and the wax.

 

[Sponsor]

 

[Tally Wacher]

You are thinking of putting silicone under the outside edge of the high part of the flange. While you could do this, I think an acrylic caulk, such as you will use around the base of the toilet, would be good too. Less expense and potential mess.

If you use wax, you must not lift the toilet at all once it goes down. Thus you don't want to insert shims after the toilet is down. You can position the shims before, tape them in place in a hidden way, and then drop the toilet. Alternatively, you could use a waxless seal. Those can conform. However your idea of using wax may be best here.

For the wax, you could use a jumbo ring as it comes. But you can mold that by hand to the shape you want. I would do that. I would wear nitrile gloves to make hand cleaning easy, although the wax is safe to handle. Anyway, after shaping, I think the top of the ring you form can be pretty much uniformly sticking up maybe 7/8 or 1 inch or so above the floor. Then lower the toilet onto the shims and the wax.

I'm going to seal that gap from the inside of the pipe/flange junction. I think that this was the cause of the sewer gases escaping into the bathroom. I'm surprised that there was no leak. As far as the shimming, I plan to dry fit the toilet and shim with composite shims, remove the toilet, place the wax ring, and install the toilet.

Maybe if I can mold the jumbo ring such that it is thinner at the back where the flange is higher and thicker at the front where the flange is thinner, the toilet will be more level.

 

[Reach4]

I'm going to seal that gap from the inside of the pipe/flange junction. I think that this was the cause of the sewer gases escaping into the bathroom.

You are talikg about the area I labeled ABCDEF, I think.
Y

Maybe if I can mold the jumbo ring such that it is thinner at the back where the flange is higher and thicker at the front where the flange is thinner, the toilet will be more level.

The levelness of the toilet is determined by the floor, toilet base, and shims.

 

[Reach4]

The molding the wax was a OCD thought.

I don't think so.

Using a level when setting the shims might be closer.

 

[Jadnashua]

Unless the wax is particularly cold and therefore stiff, it will conform to the slant of the flange without issues when you set the toilet, and nothing extra is required.

FWIW, because the outlet of the toilet is usually much smaller than the ID of the flange drain, unless there is a backup in the drain, it would not leak waste, but might leak gas.