Humidity (Moisture) in Basements

Humidity in basements is a very common problem.  The danger arises as a result of not being handled in the right manner.  Moisture problems can not only become annoying but pose a serious threat to one’s health.  That’s why it is of utmost importance to deal with any moisture problems before finishing a basement.

Knowing where the water is coming is the critical first step when trying to solve any humidity problems.  There are three sources of moisture to watch out for:

Water from rain or groundwater

Humid air that enters the basement externally and condenses on cooler surfaces

Moisture from internal sources such as humidifiers, unvented clothes dryer, bathrooms, and moisture from concrete after construction

Signs to Look For

Water leaking out of walls

Standing water on floors

Damp, humid air

Odor, mold, and mildew

Deterioration of carpet or wood

Dampness on concrete block walls


Typical Causes of Basement Humidity Problems

Inadequate Grading – Becomes a factor if the ground around a foundation is level or slopes toward the house. This can result in water to be directed into the basement.

Defective/Missing Gutters & Downspouts – Causes rainwater to be directed toward the perimeter of the foundation.

Improperly Designed Window WellsWindow wells are like a drain right next to the basement wall.  A  sign of poor design is if it directs water toward your home rather than away.

Ineffective Drain Tile & Sump PitThese systems sometimes do not work for a variety of reasons:

Broken drain tiles

Clogging of the pipe with silt or debris

Broken connection to the sump.

The sump pit usually contains a pump designed to lift the water to the ground surface outside the foundation wall.  This pump can fail.

Structural cracksConcrete and concrete block foundations usually develop some cracks.  Another cause can be soil settling.


Know the signs and ensure that basement humidity is not a threat to you or your family.