Flange/Waste Pipe Overlap?

[Pizzle2264]

I'm replacing a closet flange in a bathroom with tile floor and a concrete subfloor. When I dry fit the flange, it overlaps with the waste pipe about 7/16" at the lowest point. Is this enough overlap to form a good seal when I cement the two together? If not, how much concrete should I chip away to ensure a good seal?

 

[Reach4]

I don't know. But if you describe what you are connecting to below the floor, we may be able to identify a different closet flange.

Example 1: you have a vertical 3-inch PVC pipe, with 3.0 inch ID, that has concrete on the outside, and you are looking to connect to the inside of that pipe. The top of that pipe is 3.375 below the finished floor level.

example 2: You have a 4 inch hub (4.5 ID) that you want to drop a flange into. The top of the hub is 3 inches below the floor level.

example 3: you have a 3.5 inch OD pipe and you plan to glue a flange to the outside The top of the pipe is 3 inches below the floor level.

 

[Sponsor]

 

[Pizzle2264]

I don't know. But if you describe what you are connecting to below the floor, we may be able to identify a different closet flange.

Example 1: you have a vertical 3-inch PVC pipe, with 3.0 inch ID, that has concrete on the outside, and you are looking to connect to the inside of that pipe. The top of that pipe is 3.375 below the finished floor level.

example 2: You have a 4 inch hub (4.5 ID) that you want to drop a flange into. The top of the hub is 3 inches below the floor level.

example 3: you have a 3.5 inch OD pipe and you plan to glue a flange to the outside The top of the pipe is 3 inches below the floor level.

The waste pipe is 3.5" OD and my replacement flange will fit over the outside. The flange is high enough (I'll actually have to trim a bit off so that it sits flush with the finished floor, if I don't chip out any concrete).

 

[Reach4]

If you glue the flange in place, you would prefer a stainless steel ring.

Let's let others look at your photos too.

Is the top of your pipe about an inch lower than the finished floor surface?

I wish I could find vertical dimensions for a C40320, or an Oatey 42253, outside compression closet flange. https://xrefs3.plumbersstock.com/JonesStephens/Product-Spec-Sheet---c40320.pdf has a lot of horizontal dimensions.

Compression flanges have the advantage that you get do-overs, where you need to get glued flanges right the first time.

 

[Pizzle2264]

Yes, the top of the waste pipe is about 1 1/4" below the finished floor surface. Then there's roughly 3/4" from the top of the pipe to the concrete below that would limit how far down I can push the flange - my primary concern is that 3/4" overlap between the flange and waste pipe won't be enough to create a quality bond.