Why You Don’t Want a Humid Basement
You don’t want a humid basement because humid basements are a petri dish for mold and mildew and some of the air in the basement flows up and into the rest of your home. That means potential respiratory problems for anyone living in the home as they inhale various allergens.
Damp, humid basements also can’t be used as living spaces. Damp basements are also not a good place to store anything valuable. The most you can do with a damp basement is use it as a laundry room.
Finally, a damp, humid basement lowers your property value.
Signs of a High Basement Humidity Level
Signs your home’s basement might be more humid than it should be include:
- There’s water coming through one or more foundation walls – This is a sign of excess water in the soil outside the foundation wall, poor drainage, and a build-up of hydrostatic pressure. Water is being pushed through the foundation wall and into the basement.
- The basement walls feel damp – This might be from excess moisture outside the foundation wall or condensation.
- There’s standing water in the basement – This is an obvious sign something is wrong.
- There’s a ring of dampness around the base of the basement wall – Water is being drawn up through the concrete via capillary suction.
- The basement feels humid – If it feels humid, it probably is humid. Have you used a hygrometer to test the basement humidity level?
- There’s condensation on basement walls, floor, and other surfaces during the summer – This happens when the warmer outside air flows in and comes into contact with colder basement surfaces.
- There’s a musty smell in the basement.
- Carpet or wood structures in the basement are moldy and/or deteriorating.
- There’s efflorescence on the walls or floor – Efflorescence is salt deposits left behind after water intrusion. It has a chalky appearance.
- There are water stains on the walls or floor.
How to Lower Basement Humidity
Use a Dehumidifier And/or Air Conditioner During the Summer
If the problem is happening during the summer, the solution is to make sure the warmer, more humid air can’t enter the basement during the summer. You could do this by closing the windows and running a dehumidifier. (You could also run an air conditioner. However, a dehumidifier works best for dehumidification and it works for the entire house.)
Crack the Windows During the Winter
During the winter, when the air is colder outside, you could do the opposite. Crack the windows to allow fresh, dry air to enter the basement.
Use Vents and Exhaust Fans
How you lower the basement humidity level depends on what’s causing the excess humidity. If an unvented clothes dryer or a shower is causing the increased humidity level, the solution is to vent the dryer or install an exhaust fan in the shower.
Install a Drain Tile System
If your basement is humid because there’s poor drainage around your foundation and hydrostatic pressure is pushing water through the foundation wall, there’s only one truly effective solution: a drain tile system.
How a Drain Tile System Works
A drain tile system works by preventing excess water from building up in the soil around the foundation. There are two types of drain tile systems: exterior and interior. The exterior drain tile system is installed along the perimeter of the foundation wall at the footing level, while the interior drain tile system is installed under the basement floor. Both involve using a buried perforated pipe to channel excess moisture toward a sump pit, where it’s ejected away from the foundation via a sump pump.
A drain tile system is not a DIY project. An exterior drain tile system involves excavation down to the footer level, and an interior drain tile system requires using a jackhammer to break up the basement floor. Most people hire a foundation repair contractor to install a drain tile system. For more information, see How Does A Drain Tile System Work?