What Flange Extender Method is Best for a Brass Flange 13/16" Below Tile?

During a bathroom remodel, adding a thick subfloor and premium tile often leaves the original brass toilet flange buried deep in the floor. A flange sitting 13/16" below the finished tile level is too deep for a standard "jumbo" wax ring to seal reliably. Because your plumbing uses a brass flange soldered to a copper closet bend, you cannot easily "unscrew" or swap the flange. You need a structural extension method that creates a watertight bridge to the new floor height.

1. The Recommended Solution: The "Set-Rite" Extension Kit

For a depth of 13/16", the Set-Rite Toilet Flange Extender Kit is the professional recommendation. Most standard "stackable" plastic spacers are prone to leaking at these depths, but the Set-Rite system is unique because it is IAPMO listed and includes a specialized foam gasket that seals the transition between the old brass and the new PVC extension.

The Depth Factor: Standard spacers usually only go up to 1/2". Set-Rite kits come with various spacers that can easily clear the 13/16" gap while maintaining a uniform 3-inch or 4-inch interior diameter.
The Seal: It uses a proprietary gasket that compresses against the existing brass rim, preventing sewer gas (hydrogen sulfide) from escaping between the layers.

2. Why Traditional "Stackable Spacers" Often Fail at 13/16"

You may see "Oatey" or "Sioux Chief" stackable rings at hardware stores. While these work for 1/4" gaps, using them for 13/16" presents several risks:

Caulk Failure: You would need to stack three or four rings, with a bead of 100% silicone between each layer. At 13/16", the stack becomes unstable and the silicone is more likely to blow out under pressure or during a plunge.
The "Lip" Issue: Many stackable rings do not have a "sleeve" that extends down into the pipe. This leaves a raw "shelf" where waste can snag, leading to chronic clogs.

3. The "Deep Seal" Wax Ring with Horn (The Backup)

If you absolutely cannot use an extender kit, some plumbers use a double wax ring method, but this is not recommended for a 13/16" gap.

A 13/16" gap plus the height of the toilet's "horn" (the exit) usually exceeds the reach of even a jumbo wax ring.
The "Horned" Ring: If you must use wax, you would need a "Reinforced Wax Extender" which has a plastic funnel (horn) that reaches down through the gap. However, at nearly an inch of depth, the wax is likely to shift or "pancake" sideways over time, causing a slow leak that rots your subfloor.

4. Step-by-Step Installation for 13/16" Depth

To successfully extend a recessed brass flange, follow this mechanical process:

Clean the Brass Rim: Use a wire brush to remove all old wax and corrosion from the brass flange. The surface must be perfectly flat and silver/gold in color for the extender gasket to seat.
Dry Fit: Place the extender and the 13/16" worth of spacers (usually one 3/4" and one 1/8" or similar) to ensure the new flange sits exactly on top of the tile.
Seal the Base: Apply a bead of 100% silicone or use the provided foam gasket between the brass flange and the first spacer.
Anchor to the Subfloor: This is the most important step. You must use extra-long stainless steel screws (3-inch or 3.5-inch) that pass through the new flange, through the spacers, through the old brass flange, and deep into the wooden subfloor or joists.

5. When to Call a Plumber for a "Cut and Re-Solder"

If the existing brass flange is cracked, loose, or heavily corroded, extenders will not work.

A brass flange is soldered to the copper pipe using a "sweating" technique.
If the flange is structurally unsound, a plumber will need to desolder the old brass ring and solder a new Deep-Seal Brass Flange at the correct height. This is a permanent, "forever" fix but costs significantly more than an extender kit.

Conclusion

When a brass flange on a copper pipe sits 13/16" below the tile, the best method is a mechanical extender kit with an integrated sleeve and gasket. This ensures that waste transitions smoothly from the toilet into the copper closet bend without hitting "ledges" created by stacked rings. By anchoring the assembly with long stainless steel screws into the structural subfloor, you create a stable platform that protects your new tile and prevents catastrophic water damage.