Your toilet tank is cracked.
Toilet leaking through floor when flushed.
Place the small container underneath the valve in case some water leaks into it while you do the repairs.
A toilet leak is usually a result of some sort of a break or defect in the seal of the wax ring that adjoins the toilet to the floor.
The water damage in the floorboard suggests there is a plumbing leak above the floor.
Often referred to as a spud washer.
You can do this by turning the valve by the toilet base clockwise.
A leak can be cleaned up but damage to a floor will cost significantly more to repair.
Your supply valve or fill valve are loose.
It happens to households every day and occurs for a variety of reasons.
It will fit most models and is the best one by far in my opinion.
If you have a wobbly toilet tank it also means that this gasket is not sealing properly and hence the water will leak when the toilet is flushed.
If water leaks between the toilet tank and bowl whenever you flush your toilet you need a new tank to bowl gasket.
When the upstairs toilet is flushed water apparently leaks thru the floorboard onto the ceiling in the room downstairs.
The gasket could also be worn out.
Toilet leaks through floor when flushed the second floor toilet is leaking to 1st floor ceiling when flushed.
No matter what type your toilet is use the pink colored crane gasket.
Now it only leaks if flushed and the water dripping is clear.
Then follow our step.
The nuts and bolts connecting the tank to other parts of the toilet aren t tight.
Before the toilet was leaking even when not used and everything was replaced toilet flanged and wax ring.
When your toilet leaks when flushed between the toilet tank and the bowl the culprit there is the toilet tank to bowl gasket which is also known as a spud washer.
Have just noticed that when you flush toilet on ground floor concrete floor slab it bubbles and you can see the water coming up when you flush where toilet pipe goes into waste pipe in floor.
If you discover the base of your toilet is leaking it s important to act quickly before there is water damage to the floor.
Then flush the toilet to empty the tank.
The upstairs toilet shows evidence of leaking.
A leak in the base of the toilet is common.