Often times a toilet will develop a small leak where it meets the floor. Sometimes your only clue will be a wet rug, sometimes it’s much more obvious. If there are no signs of leakage at the valve, supply line or tank area chances are good it’s the wax seal that’s leaking. The wax ring that is used to seal the toilet to it’s mounting flange is not reusable and will need to be replaced with a new one.
All it takes is for the closet bolts to loosen up the smallest amount and allow the toilet to move for the wax seal to be compromised. When this toilet was set previously, the metal washers were placed directly on the porcelain and they rusted. When the washers rust they get weaker and flex, allowing the toilet to move and the wax seal to leak.
Once the toilet is pulled, the wax seal can be inspected. Regardless of it’s condition, it needs to be replaced as they are not reusable. This one was leaking due to the previously mentioned movement. You can see the discoloration and moisture in the picture.
After the old wax seal is removed, the closet flange can be inspected. This one was in fine shape and mounted securely to the sub-floor. If it weren’t in good shape, now would be the time to repair the flange. If leaks go untended structural damage can occur. Even small leaks can cause large amounts of damage to the sub-floor and joists.
After the new wax seal is installed the toilet can be reset. This time the plastic washers are installed under the metal washers. This will keep the new metal washers from rusting and make sure this toilet doesn’t begin to loosen up and leak in the future.
Now that the toilet is reinstalled, it can be tested. After it’s been checked for leaks the plastic caps are installed over the hardware and a bead of caulking is run around the base. While this toilet may look the same as it did earlier, it is now leak free and ready to use.