Can I Use 6 Mil Plastic to Waterproof My Basement?

Effects of Moisture

• When moisture levels are too high inside your basement, it can cause your whole home to feel damp and humid. Walls and ceilings often develop water stains when improperly waterproofed. Basements with dirt floors are at an increased risk of moisture problems as moisture can migrate through the basement and into your home. Constant moisture inside your basement will eventually lead to mold and mildew growth. Mold-causing fungi begin to grow when they find moisture inside your home. Once mold and mildew are present, your basement will smell damp and musty. The structure of your home may also suffer damage from mold and mildew development. Homeowners who are exposed to mold growth often suffer physical symptoms that can become serious.

Moisture Causes

• According to the Centers for Disease Control (CDC), water marks on basement floors or walls are a sign of inadequate waterproofing. Most basements will begin to leak 10 to 15 years after construction, even with some moisture control methods in place. Older homes often develop cracks in the foundation over time, which is a common cause of excess moisture inside your home. Homes with an improper final grade are prone to water leaks because the soil is sloped toward the foundation, allowing water to run inside. Homes that do not have rock, gravel or sand underneath the foundation are prone to excess moisture as well. Failure to place 6 mil plastic sheeting underneath the home is another cause of moisture damage.

Solution

• Placing a moisture barrier over the floor of your basement will help slow down migrating moisture. According to the North Carolina State University Cooperative Extension, homeowners should cover the ground underneath the home with 6 mil plastic sheeting. At least 70 to 80 percent of the soil beneath your home should be covered with plastic. Anchor the plastic along the foundation wall for optimal moisture control.

Considerations

• There are other things you can do to reduce humidity and excess moisture in your home. Inspect the area around your home to determine if excess moisture is seeping inside. Keep your gutters clean and trim shrubs growing close to your home. Thick shrubbery can prevent adequate air circulation and promote dampness. Install ventilation fans in humid rooms, such as kitchens and bathrooms, to keep humidity levels low. Running your air conditioner, when the humidity levels exceed 50 percent, will also help reduce humidity. Inspect your basement for gaps and cracks where air can leak inside and seal them with caulk. Regrade the lot your home is built on if the soil slopes toward the foundation.