One Clever Reason to Put Bubble Wrap Inside Your Toilet Tank

If you have a sweaty toilet, you probably don’t have to worry—and there’s an easy fix that involves bubble wrap! According to Paul Abrams, a spokesperson from Roto-Rooter, toilet tank sweat isn’t a plumbing problem or tank leak. Instead, it’s condensation that usually occurs when the water inside the toilet tank is far colder than the air temperature inside the bathroom. 

Humidity also plays a role, he says: condensation tends to build up when the air is moist and humid—like after you take a hot shower—and it’s more pronounced in homes without air conditioning.

While a bit of toilet tank sweat every now and then isn’t necessarily something to worry about, that condensation can be harmful if it happens for an extended period, particularly when it drips to the floor or the wall behind the toilet. “Over time, it can cause damage to wood flooring or get beneath linoleum and other flooring materials and damage the sub-floor, and it can also damage sheetrock and plaster,” Abrams says.

On top of damaging these materials and costing you money, Abrams says excess moisture may promote the growth of mold or mildew, which can potentially lead to respiratory issues for anyone who lives in your home. 

If you’re noticing your toilet is developing condensation, there’s a super simple, DIY way to prevent it: a layer of bubble wrap insulation inside the edges of your toilet tank.

The hack doesn’t have to cost you anything if you have bubble wrap on hand, but Abrams says if you can also opt for a layer of rigid or flexible foam insulation. “Any type of insulation layer between the water and toilet tank will reduce the amount of condensation on the outside of the tank,” he says.

Rather buy than DIY? Many stores also sell kits to insulate a toilet tank, which Abrams says can be just as effective as the bubble wrap trick. Basically, these work the same way by creating a barrier between the warm outside air and cold water inside the tank (you’ll just need a pair of scissors to cut yours down to size). 

Another way to deal with condensation is to treat the symptoms. Abrams recommends reducing humidity in the bathroom during or after a hot shower or bath by turning on the air conditioner, turning on the bathroom’s ventilation fan, and, if you can, leaving the bathroom door open. You can also try keeping a small dehumidifier in the bathroom.

If these measures, coupled with bubble wrap or an insulation kit, don’t do the trick, there’s one last thing you can try before you call your plumber and dish out money for repairs: replacing your flapper valve. 

“If [the flapper valve] is leaking water into the bowl, your toilet is constantly having to refill itself with cold water,” he says. “This could be contributing to your problem since water that stands in the tank for a while should warm up over time and will eventually be closer to room temperature between flushes.” 

If you’ve tried everything but still have heavy condensation on the toilet tank, a plumber can install a mixing valve to feed warmer water into the toilet tank—but this issue might be more common in homes that source very cold water from a well.