How to Eliminate Toilet Tank Condensation

A problem experienced by many homeowners is that of the sweating toilet tank. This occurs when water temperature in the toilet tank is substantially cooler than that of the air surrounding the tank. As the warmer air from the bathroom makes contact with cooler wall of the toilet tank condensation forms on the outside wall of the tank, and under severe conditions can result in significant levels of water being deposited beneath the tank. This can result in any number of problems including warping and rotting of wooden floors.

Surprisingly, this condition can exist in both winter and summer months. In winter frigid outside air cools the toilet water supply pipes resulting in very cold water being pumped into the toilet tank that has been warmed to room temperature in the heated house, causing almost immediate and heavy condensation on the tank.

In summer the warmer temperatures result in high humidity. When warm air with high concentrations of moisture (humidity) make contact with the cooler surfaces of the toilet tank heavy condensation occurs.

Fortunately, there is a relatively simple solution to this problem that can be completed by the unskilled homeowner with very little effort and expense.

To solve the problem you must first purchase an inexpensive toilet tank insulation kit, which can be found at most home improvement stores.

Next, remove the lid from your toilet tank and set it aside, taking care to not drop the lid as these are easily broken.

Look inside the tank and note the water level inside the tank. Mark the water level with a piece of masking tape or with a pencil mark.

Turn the water supply valve to the toilet “off” and flush the toilet. To empty as much of tank water as possible hold the flush handle down until the water is drained. Use a sponge and/or paper towels to soak up as much of the remaining water as possible.

Once all visible water has been removed use an electric hair dryer to completely dry the bottom and sides of the tank. Allow the tank to air dry for another 30-45 minutes.

While the tank air dries follow the instructions in the insulation kit to measure and cut the foam insulation to fit the bottom and all four sides of the tank. The insulation kit will provide a cutting guide to facilitate cutting the bottom piece of insulation to fit around the tank overflow pipe and flapper valve.

Use a tape measure or ruler to determine the distance from the bottom of the tank to the water level mark previously made and marked with masking tape (or pencil) and add two inches to this measurement to determine the cut length for the four side pieces of insulation.

Once all the insulation pieces are cut to size test fit these in place and make any cutting adjustments required to provide close fit.

Install the tank bottom piece first by applying a bead of insulation adhesive (provided with the kit) along the outside edge of the four sides the bottom piece of insulation and press the insulation firmly in place.

Next run a bead of adhesive around the four edges of one side piece of insulation and place snuggly in place abutting the previously installed bottom insulation.

Repeat the previous step for the remaining three side pieces taking care to ensure that adhesive is applied on all four sides of each piece and between every seam between adjoining pieces.

Allow the adhesive to dry for 24 hours before refilling the tank with water.

Following less than one hour of work and very little expense the average homeowner can eliminate problem associated with toilet tank condensation.