Rocking Toilet Leaks When Flushed

Flange and Wax Ring

The toilet's horn, or the opening in the bottom of the toilet where the waste water flows out, connects to the drainpipe in the bathroom floor with the aid of a two-part seal. The closet flange anchors directly into the floor with several screws. The closet bolts also anchor into the flange, keeping the toilet securely in place. The wax ring sits on top of the flange and around the horn on the toilet, keeping the water flowing out of the toilet from going anywhere other than the drainpipe.

A leaking toilet can cause severe damage to a building, including structural damage, if the leaking goes unchecked long enough. Finished bathroom flooring may warm and peel up, especially if it is linoleum, and must be replaced. Leaking water can damage the ceiling below as well as any light fixtures The presence of moisture in the subfloor can lead to the joists rotting and even mold growing throughout the subfloor.

If you caught the leak early enough, repairing the damage will not require much work. You will not be able to know if the flange or wax ring was the source of the leak until you unseat the toilet and look for damage on the flange. If the flange is intact, the wax ring likely was compromised by the toilet's rocking. If the flange was broken by the rocking, you must anchor a repair strap over the flange to prevent future leaks. Scrape off the old wax ring and install a new one.

Replacing the wax seal or attaching a repair strap over the flange will not ensure that the leaks stop--unless you also take steps to keep the toilet from rocking in the future. Toilets rock when they are not anchored properly. Before tightening the nuts on the bolts after reseating the toilet, compress the wax ring to the point that the entire base of the toilet touches the bathroom floor. Pushing on the toilet bowl will compress the wax ring or, if necessary, you can sit on the bowl carefully without rocking it, until the wax ring compresses. Only tighten the nuts onto the bolts until you feel resistance. Otherwise you can crack the toilet's base instead of it just being loose and rocking.