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Toilet Tank Condensation Problems and Fixes

There is a lot of condensation on my toilet tank, and its drips on the floor. Can I prevent this, and will it cause any damage to the toilet or floor?

Condensation is caused by cold water entering your toilet tank causing a drop in temperature on the outside surface of the tank. During humid weather, the tank temperature can be low enough to cause the moisture in the air to condense on the tank surface.

The problem starts when the condensation begins to drip on the floor. Water damage to the floor itself and loosening of floor tiles are likely.

If the dripping is heavy enough, and the water gets under the toilet or around the closet bolts (the bolts that hold the toilet down to the floor), corrosion and eventual failure of the floor flange can occur. 

In some older toilets, the bolts that connect the tank to the bowl can also corrode. This can lead to loosening of the toilet and a potentially expensive leak. Click the question: When I flush the toilet, I noticed that water seems to leak on the floor from between the tank and the bowl. How can I repair this? if you want to see what hell you can go through if you don't do something about severe condensation!!

Here are some fixes you might want to try:

The best fix for an individual toilet (if you have the patience to do it right) is the Toilet Tank Liner Kit...

You can purchase a kit that lets you line the inside of your toilet tank with insulating foam. This is a fairly good fix, but a pain to install. Take your time, get the cuts right, and don't try to "cut corners"... buy one extra kit when you buy them. If you screw up a cut, you get a second chance without having to make a trip back out to the hardware store. If you are anything like me, you will be tempted to try to "make do", which is not very professional. Do it once right and it will last you for many years!

You must scrupulously dry the inside of the toilet before gluing in the insulation. Other than that, follow the instructions and you should come out with a good job.

You will still get condensation on the metal intake tube. But if you replace the metal tube with a polybutylene (plastic) intake tube, you eliminate that problem, too, Plastic usually doesn't sweat because it is a better insulator than metal tubes. Click the question: How do I install a new intake line to my toilet? for help with the intake tube installation or replacement.

Condensation catcher tray thing:

There is a gizmo (the "official" name eludes me) that I have installed for a few customers with mixed success. It is a plastic tray that actually hangs under the toilet tank from long flat metal straps that bend over the top of the tank and under the tank cover. The condensation drips into the tray. The tray has a drain hole with a tube attached. The tube runs to a bottle you keep on the floor, and you empty the bottle when it fills. Sort of like a toilet catheter, for those of you with a medical background.

The principle is good, but unfortunately the tray usually does not catch all the condensation. It is, however, less daunting a project than the toilet tank liner, so I would suggest that if you do use one of these, and you have a very severe condensation problem, put a towel on the floor behind the toilet to catch anything the tray misses.

Cover your toilet tank with an old towel...

Just kidding about the towel.  What I really mean is installing a toi let tank cover... a decorative blanket-wrap that both dresses up the tank and also is highly absorbent.  For all but the most serious tank condensation problems, a tank cover may be a godsend.  Installation is a snap, and the only maintenance is to occasionally throw it into the washing machine!

You may find them at many of the large chain stores, such as Walmart or J.C. Penney.  As of this writing, J.C. Penney has them in their online catalogue, too!

The ultimate and permanent solution to all condensation... Install a mixing valve to warm up the cold water coming into the toilet!! Or, I guess you could move to Nevada...

No, don't pack up and move to Nevada! No offense to Nevadanites, though I would be surprised if many of you from the drier, warmer climes would be reading this anyway!!

It probably would be cheaper than moving, though maybe not too much!  The solution is just too simple: install a mixing valve that combines a little water from your hot water line with the cold water line, just raising the temperature enough to minimize condensation.  You wouldn't want to do this for all your water, though, since drinking hot water from the tap might not be the best thing, especially if you use a gas or electric hot water tank, since the water from the tank can have a greater concentration of minerals than your regular tap water.

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