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.

Changing a Toilet Wax Ring Ebook

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.


For information on installing a shower pan membrane liner for a ceramic tile shower, see the Shower Pan Membrane Liner Installation eBook from HomeAdditionPlus.com.  The Shower Pan Membrane Liner EBook will quickly teach you the step-by-step process for installing the shower pan membrane liner correctly. It includes instructions on framing the shower stall, pouring the pre-slope and shower base mortar, and installing the shower pan membrane liner.

For information on how to tile a custom ceramic tile shower, see the “How to Tile a Custom Ceramic Tile Shower eBook” from HomeAdditionPlus.com. This eBook will quickly provide you with step-by-step instructions on how to measure and install ceramic tile in a shower, including the installation of tile on shower walls, floors and curbs. It provides detailed instructions for every step in the process of tiling a custom ceramic tile shower and is loaded with instructional pictures!

Related Information


Additional Plumbing Resources from Amazon.com


Get Free Bathroom Remodeling Price Quotes with No Obligation!

Fill out our 3-5 minute quick and easy form, and receive a free price quote on a bathroom remodeling project from one of our pre-screened and licensed bathroom remodeling contractors. This process is free and there is no obligation to continue once you receive your bathroom addition price estimate.