Condensation on toilet tanks is created because the tank is colder than the surrounding air.  The tank is colder because of the cold water that is entering the tank each time the toilet is flushed.  In most cases homeowners find that the condensation is more prevalent in summer months when the ambient air is carrying much more humidity.

There are four methods that one can use to eliminate or greatly reduce the condensation on the toilet tank.  Besides the four methods described, homeowners should evaluate their bathroom ventilation systems to ensure that they are removing excess moisture from the room.

1. Toilet Tank Cover

Toilet tank covers were very popular in the 60s and 70s.  However, they do not appear to be in style at the moment.  Finding a cover that suits the aesthetics of your bathroom may be difficult.

2. Insulating Liner

Insulating liners are available as kits at most hardware stores and the big box home improvement centers.  They are made from a polyurethane foam and glued to the inside of the toilet tank, providing an insulation barrier from the cold water to the porcelain tank.

 Toilet tank liner

3. Mixing Valve

A mixing valve, while a little more complex to install will definitely solve the condensation or sweating problem of the toilet tank.

The mixing valve adds hot water to the cold water entering the tank.  By setting the tank water temperature to the approximate temperature of the room, condensation cannot form form.

There are numerous styles of toilet water mixing valves and they are available at most plumbing supply stores.

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