The reason being is because the toilet recesses into the flange when.
Toilet flange is level with floor.
This can be a very serious issue since it can cause some sewer gases to leak around the bathroom.
Take for instance tiling a new bathroom floor that ended up raising floor height way above the toilet flange.
If the toilet flange is at the incorrect height it will cause problems with the toilet connecting onto the plumbing.
To get the necessary clearance from the floor you can add a toilet flange extender which is quick and easy to install.
Place the carpenters level across the toilet bowl side to side and note where the bubble level is.
Most extenders come with long bolts which may be necessary if the flange is below the floor level.
When you install your toilet flange it should be installed on top of the finished floor and it should also be installed perfectly level.
If your flange sits even or below the floor then it s wrong.
This is very important.
If that s the case buy a repair flange to fit over the existing one.
In newer homes the closet flange may be fixed to the drain with pvc glue.
These models may feature an additional metal or plastic ring that sets directly on the polished floor but is hidden by your toilet once it is reinstalled.
It has to sit evenly on top of the finished floor.
Ideal height of toilet flange.
Toilet installations sometimes get undesirable results when not properly set up.
If the previous flange is too low purchase one that is designed to sit on the finished floor and provide the optimum toilet flange height.
Flange extenders are commonly sold in 1 4 inch and 1 2 inch sizes to raise the height of the existing flange 1 4 or 1 2 inch.
Hammer a shim gently between the floor and the toilet base to bring a low side up.