How to Prevent Basement Condensation

How to Prevent Basement Condensation. Does your basement smell musty? Can you feel moisture in the air when you go down there? Maybe even actually see water on the floor?

Prevent Basement Condensation

You could have a leaky foundation, but hopefully all you've got is moisture condensing out of warm, humid summer air when it gets down into the cool of your basement. Wherever that moisture is coming from, you need to deal with it. Even condensation can be hazardous since it can lead to mold formation and all its related health hazards. Here's how you can figure out if the moisture in your basement is from a leaky foundation or condensation--as well as some ideas for stopping that condensation from ruining your basement.


If you have a well water pressure tank, wrap that as well to prevent condensation. An insulating blanket for a hot water heater may fit or you could use fiberglass insulation wrapped in a sheet of plastic (to act as a vapor barrier).


Don't think that moisture in your basement is just a sign of summer and will go away when the weather gets cooler. Mold and mildew love damp conditions, and moisture can get right into drywall and create a prime environment for it to grow.

How to Find Out Where the Moisture is Coming From

  1. Determine if the water on your basement walls is from condensation or migrating in through the foundation wall. This is straightforward and easy to do. Start by drying off a section of your basement wall about a foot square, then cut a piece of aluminum cooking foil, just a little smaller in size.

  2. Apply duct tape completely around all four sides and tape the foil to the wall.

  3. Leave the foil in place for at least 24 hours and then remove it. If the moisture is on the side of the foil facing away from the wall, it's condensation and easy to deal with. If it's on the side of the foil facing the wall, it's coming through the wall.

How to Deal With Condensation Moisture

  1. Dry out or remove any furniture, clothes or even building materials that have become damp. Opening basement windows and installing a fan will keep the air in the basement circulating and help dry things out, however, you need to eliminate the moisture or it will come back.

  2. Understand that the recommended humidity level in a home during the summer is below 65 percent (to minimize potential mold growth). Either a dehumidifier or a room air conditioner will remove moisture from the air (anywhere from 10 pints all the way up to more than 50 pints per day). However, a dehumidifier is considerably less expensive than a portable air conditioner ($200 to $300 versus $600 to $800).

  3. Set up a dehumidifier in your basement and leave it on until the humidity drops below 65 percent. All dehumidifiers have a storage tank to hold the water they remove from the air. Even better, many can actually be attached to a drain hose so you don't need to be constantly emptying the tank.

  4. Insulate all cold water pipes with foam insulation tubes available at home and hardware stores. You need to cover the entire length of the pipe, because when humid air comes in contact with exposed pipe, it will drop its moisture on the pipe surface, then drip onto the floor.