A leaking toilet can cause damage not only to the bathroom's floor but also to the room below the toilet, the subfloor and floor joists. Once you discover the toilet leaking, take steps to stop the leak so the toilet can be used once again.
Water Damage and Mold
Leaks from the bottom of the toilet, whether large or small, can lead to larger problems if left unchecked. Once you notice water pooling around the base of the toilet or leaking through the ceiling below, stop using the toilet immediately or the leak will continue. Leaking water can damage the bathroom's finished flooring, the ceiling in the room below and lights in the room below. Leaks can even cause mould and rot in the subfloor.
The toilet sits on a seal made of two parts. The flange is a ring that anchors directly into the bathroom's finished floor. The closet bolts, or the bolts coming through the toilet bowl's base, anchor into slots in the flange. The wax ring sits between the bottom of the toilet and the flange. The wax ring and the flange combine to make a watertight seal.
Removing the Toilet
To fix the leak at the toilet's base, first close the toilet's water valve and use a wrench to remove the water line from the water valve's body. Flushing the toilet once will drain water from the tank. Remove the nuts from the bolts on the toilet base, then lift the toilet up off the bolts.
Replacing the Seal
Scrape off the old wax seal with a putty knife. With the wax seal removed, you can look over the flange for any damage. Repairing the flange takes anchoring a repair strap over the flange. You must also place a new wax seal over the flange or repair strap, with the flat side of the seal pointing down. Set the bowl down slowly over the two closet bolts protruding up from the floor. Before tightening the nuts on the bolts all the way, push down on the bowl so the base touches the finished bathroom floor. Only tighten the nuts until you feel resistance; otherwise you can crack the toilet's porcelain base.