Signs & Symptoms of a Leaking Seal on a Toilet

Where to Look

• Follow the water leaks, streaks and discolorations. When the water leak is coming from anywhere but the base of the toilet you do not have a leaking seal. Look for the source of the problem to be around the base of the toilet. Examine the floor around the toilet base for discoloration, decay and warping. Leaking toilet seals on upper floors cause damage to ceilings underneath them. Look for water stains, warping or cracks in the ceiling. Drip marks along walls or on the floor directly under the toilet above indicate possible leaks.

Identification

• Smell the air in the bathroom. A strong smell of sewage is a sign of a potential leak. Attempt to move the toilet from side to side. A rocking toilet indicates either an improperly set flange or a failing subfloor; either of these can cause the wax seal to break. Mold around the toilet base, a soft spongy floor or visible signs of the toilet settling into the floor indicate more severe water leaks and a failed seal.

Causes

• If the flange is more than 1/4 inch below the floor surface a space exists between the seal or toilet and the flange. Conversely if the flange is raised above the floor the toilet cannot sit evenly on the flange causing the seal to break. Look for damage to the exterior side of the slot that holds the flange bolt in position; a broken slot allows the flange to rock, causing a leak. If the floor around the flange is warped or rotted gaps around the flange will appear causing an outlet for water. If the wax seal is old, it can warp, crack or degrade allowing water to seep through.

Potential Problems

• Improper seating of the seal is one of the more common problems related to future leaks developing. Other indicators include an unleveled toilet caused by either improper tightening of the bolts at the base or wear on the bolts over time causing them to become loose. A seal not replaced over many years dries out; if the seal has never been checked since you remember, this could become a problem. Renovations that raise the subfloor or new installations where the flange does not come within 1/4 inch of the floor surface will cause future leaks. Old flooring that was not replaced or firmed up can dislodge or rot away from the exterior of the flange causing gaps around the flange and seal.

Repairs

• The most common repairs involve either raising or lowering the flange and installing a new wax seal. Raise the flange with a flange extension allowing it to meet the floor. Raise the floor with shims for a flange set too high. Replace the wax ring regardless of its condition to ensure you have a good seal.