Most basements, by the sheer nature of the fact that they are built into the ground, present the possibility that water can intrude, turning what was once a dry basement into a wet basement. This is because water in the soil can put constant pressure on basement walls. Plus, water follows the path of least resistance inside a home and over time can find its way into a basement.
Therefore, it’s important when buying a house with a basement to check for signs of dampness in the basement. It’s better to find out before you buy than afterwards, especially since you can’t rely on seller disclosures.
Signs of a Damp or Wet Basement
- Water stains along walls or floor. This could be caused by something simple such as an overflowing laundry tub or it could be a result of water seeping in through basement windows, the walls or the floor.
- Musty odor or damp smell. Excess moisture in a basement can cause an unmistakable smell.
- Mold. It could be colored black, brown, yellow or green, and you won’t know for certain if it’s mold without testing it. Often the northwest corner of a house is known as a “cold corner” and susceptible to developing mold.
- Efflorescence. This condition produces a white or sometimes grayish ash on the walls. Sometimes it sparkles. Efflorescence is caused by salt deposits left behind by evaporating water.
- Spalling. When water gets inside the surface of concrete, brick or stone, salt deposits from the water cause the surface to flake away, peel or pop off.
- A sump pump, sitting quietly in a corner, by the way, is not a decoration. It’s a sign that the seller regularly pumps out water or had a dampness problem at one time.
Potential Causes of a Wet Basement
- Ground water. Water can seep through floors and foundations due to freakish heavy rain or seasonal run-off, or it could be constant water seepage.
- Overflowing gutters. Gutters can overflow because of:
- Excessive rainfall.
- Clogging from leaves or debris.
- Improper installation, for example, draining from the second-floor gutters into the first-floor gutters.
- Sudden thaw from frozen gutters.
- Not enough gutters. Sometimes homeowners install gutters in one or two locations but not all the way around the house.
- Downspouts. Water problems can be caused by disconnected downspouts or downspouts that aren’t long enough to direct water away from the house.
- Improper landscaping or grading. This causes water to flow toward the house instead of away from the house.
- Sprinklers. If sprinklers are aimed toward the house, too much water will accumulate at the foot of the foundation and /or leak through the foundation.
- Condensation from pipes. Often, in high humidity areas, pipes will form condensation and drip, especially from air conditioner units without a release valve.
- Water leaks inside the walls. If the interior walls lead directly from the attic to the basement, it can provide a direct channel for water from the roof to seep inside the house.