Q&A for How to Replace a Toilet Flange

When removing an old toilet, the flange should remain connected to the bathroom floor so that the new toilet can be attached to it. In other words, it is meant to stay in place unless it was damaged or bent during the removal of the last toilet.

Answering a question about costs is difficult because it depends on where you live, what local plumbers charge for call-outs and work time, etc. Assuming you’re asking for a plumber to come out, this could cost roughly around US$50 to US$200, probably leaning mostly to the upper end of costs. It’s a good idea to call your local plumber and ask for a quote first, then you won’t get any nasty surprises.

As explained above, the lip of the toilet flange should sit flush on the floor all the way around. The neck of the flange should slide into the pipe snugly. An improperly fitted toilet is often caused by the flange not sitting on the finished floor but rather, sitting above it, or it is not level with the floor. It’s also important to read the industry code for toilet fitting relevant to your location and building materials, as local variations may exist.

It is best that the flange is level with the floor; the higher a flange sits above the floor, the greater the likelihood of poor fitting and problems with the toilet leaking. If the flange is sitting only about ¼ inch of the floor, it is possible to use a wax ring sealed in place to fix this small gap.

If you tilted the toilet while installing it, it could have caused the wax to squeeze out more on one side. After you placed it the rest of the way down, that now-flattened side could have left a gap, allowing smells to escape. This is why it's important to install the toilet as perpendicular as possible.

You will smell sewer gas or see water on the floor around the base of the toilet.

No, simply replace wax ring or seal (rubber gasket seals are becoming more popular). However if you notice damage to the floor, or flange, you may want to replace them depending on the severity of damage.

The bottom face of the flange should rest on (or be supported with spacer rings to be even with) the finished floor, so that the entirety of the flange is above the finished floor.

If the flange is damaged, it can be repaired with a repair ring glued on top. Otherwise, the old flange needs to be cut off.

You could use a hacksaw and angle grinder and take off the extra.

You can install a flange extender. They often come in sets of 3; install as many as you need to get the height you want.

Just at or below the finished floor, but it depends on the product being used to fix it. Some products can have a level on them that requires a lower cut.

Your safest bet is to call a plumber, but it is possible to do the job yourself--very carefully. You have to slowly chisel away the lip of the old flange, being careful not to damage the cast iron outflow pipe (or you'll be in for pricey repairs!). Then, measure the interior diameter of the outflow pipe so you can buy a PVC flange with a rubber gasket that fits snugly inside it.

It depends on the reasons you need new holes and the kind of floor you're working with. If you need new holes because the floor is damaged, then you must first repair the floor properly. If you need new holes only because the old hole has worn, but the floor is otherwise good, then your methods will differ based on the material. For wood, you can drill out the old hole(s) and glue tight-fitting wooden dowels into the holes. Re-drill into the dowel after the glue has set. For concrete, you can use a similar process, but instead of dowels, use fine mortar or mortar crack-filler. Allow it to cure for a few days before drilling new holes.

If it's a metal shaft holding the float, just bend it upwards. If plastic, heat gently with a heat gun and bend with light pressure.

If the flange is PVC, it is probably glued to a PVC outflow pipe. If it's cast iron, it's probably integrated into a cast iron outflow pipe. In either case, it is best to call a plumber. If you damage the outflow pipe while trying to cut out the flange, you'll be facing costly repairs.

You have potentially misaligned the wax ring. The other potential is just excess wax squeezed out when you reset the toilet. If you have no odor or leaks coming from the toilet, you are most likely okay.

If the toilet is otherwise installed correctly, the floor is probably uneven or has cracks in it (if it is tiled). You will probably need to repair the floor and re-seat the toilet.

If possible, yes. The toilet flange needs to be secured one way or another: either secured with glue to existing plastic pipe, or secured with screws to wood or a concrete floor. The toilet will bolt to the flange and requires a secure connection for no movement.

It should be 12 1/2 inches from an unfinished wall and 12 inches if the drywall is installed already.

Shim up the toilet to be level, then tighten bolts. Put a bead of silicone around the bottom of the base of the toilet to act as a shim when the silicone is cured.

You can find replacement bolts at any hardware store. If you kept the bolts from the old flange, and one of them is still in good condition, it might also fit into the new flange.

You will have to determine the integrity of your subfloor. Take a knife or other sharp implement and push into the subfloor. If the material is easily pushed into or crumbles, you should probably replace it. If the subfloor is hard to make a mark on, it is most likely okay.

Not usually. If it is too low in the floor, there are extenders such as Set-Rite.

Possibly, depending on the new flange design. If the toilet bowl bolts (johnny bolts) are still in the correct position with the flange rotated, then yes. That is why they are in a circular slot, to allow for alignment. Be sure that they are in the narrow part of the slot, not the wide entry area, so rotate toward the narrow end of the slot if possible.

Inside the outflow pipe. Look at the picture after step 1 of Part 4. The red gasket on the flange seals with the inside of the outflow pipe.