How to Fix a Sweating Toilet Tank

A Sweating Toilet Tank can Lead to Mold and Mildew Problems if left Unchecked

By Mark J. Donovan

During hot, humid days do you see moisture condensing on your toilet tank and then dripping onto the floor? This is known as a sweating toilet tank and is the result of a cold toilet tank surface (due to cold tap water inside the tank) coming in contact with warm, humid air. If the sweating toilet tank is not fixed, the formation of mold and mildew could potentially occur around the toilet.

Fortunately, fixing a sweating toilet tank is an easy project for the DIY homeowner. The basic project involves the installation of an insulating rubber or foam material inside the toilet tank.

To fix a sweating toilet tank first visit your local home improvement store and purchase a toilet insulation kit.

To install the toilet insulation kit, first close the supply line valve to the toilet.

Then flush the toilet a couple of times to drain the water from the tank. Clean up any residual water in the tank with a bucket and sponge. Make sure the toilet tank is completely dry.

Once you have emptied the toilet tank of water, use a measuring tape to the measure the inside dimensions of the tank.

To install the toilet tank insulation material, you can simply use a utility knife to cut the material to size for the inside toilet walls. Cut pieces for each wall of the toilet tank and then apply an adhesive to the walls of the tank. Press fit the insulation material up against the walls of the tank.

Let the adhesive dry per the manufacturer’s recommendation, and the toilet is again ready for use. Simply turn the toilet tank supply line valve to the on position and your sweating toilet tank should be a thing of the past.

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An Alternative Fix to a Sweating Toilet Tank

If you do not want to go through the process of installing insulation material in the toilet tank, alternatively you could also use a dehumidifier to lower the moisture level in the home. The only downside to this solution is that the dehumidifier would need to be operated and maintained on a fairly regular basis during the hot, humid days.

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