A dry, well-insulated basement adds valuable living space to your home. When designing and building a new home, it’s essential to protect your basement from unwanted moisture. Basement moisture can cause mold growth, which poses a health threat to anyone living in the home. While you can’t prepare for a broken pipe and the water damage it causes, you can prevent a variety of basement moisture issues.
Three Sources of Basement Moisture
Understanding where and how unwanted moisture in basements develops is key to creating a basement or lower level living space that remains dry and maintains low humidity levels. According to the University of Minnesota, every homebuilder needs to consider three sources of potential basement moisture:
- Rain and groundwater
- Interior moisture (e.g., unvented clothes dryers, bathrooms and moisture found in concrete after construction)
- Exterior humid air that penetrates the basement, condensing on cool surfaces
Prevent Basement Moisture
A rainstorm that drops 1 inch of rain into your rain gauge deposits 13,577 gallons of water onto your property, reports the U.S. Geological Survey Water Science School. If your home doesn’t have the proper protection against seepage, your basement will suffer from moisture and water damage. With a combination of techniques, you can prevent moisture and maintain low humidity levels in your home’s basement.
Know about the water table.
Before choosing a site for your new home, ask about the area’s water table. Avoid building on a high water table area that can contribute to wet conditions for your basement.
A publication from Kansas State University cautions, “When evaluating a home site, examine soil and rock profile layers for evidence of drainage restrictions. Restrictive layers are especially important in rocky areas because these layers will impede drainage.”
Is your property on a hillside? A cut-off drain may be needed to divert water away from the home’s highest side.
Know your soil.
Certain soil types contribute to foundation issues and moisture problems in a basement or crawl space. A drainage tile system is essential, especially if your soil has a high gravel content or is sandy. If you have clay soil, known as expansive soil, it’s essential to address drainage issues to avoid water problems and potential foundation damage.
Build on highest part of property.
One of the best ways to avoid basement moisture is to build your home on the highest part of the property when possible. Fill in the area around the home so the soil slopes away from the structure. The slope should grade at least 6 inches in the first 10 feet. The soil around a new home or building structure does settle during the first 12 to 15 months after construction. Because of this settling it’s recommended to refill after a year in order to maintain the necessary slope.
Install proper drainage systems.
It’s also recommended to have 4-inches of gravel under the basement’s slab to aid in drainage. In addition, gutters and downspouts must be installed with the downspouts expelling water away from the home without sending that water into the perimeter drainage tiles. A drainage tile system diverts water away from the home’s foundation, working to keep the basement dry.
Failure to improperly install gutters/downspouts or a subsurface drainage tile system can cause long-term problems. Water that doesn’t drain away from the home increases the risk of foundation cracks and serious water damage over time.
Invest in basement waterproofing.
An exterior waterproofing coat can help reduce basement moisture and mold growth. This type of protection helps maintain stable temperatures within the lower level space, can reduce condensation issues, and even help to decrease foundation cracks.
Allow basement to dry thoroughly.
The cement used to form your basement has a high water content. After the basement’s completion, run a dehumidifier for about 60 days to reduce humidity caused by the water’s evaporative effect.
After moving into your new home, keep humidity levels low and moisture at bay in the basement by insulating all cold water pipes, venting the dryer to the outdoors, and running a dehumidifier as needed.
As the Vice President of Operations for DKI Commercial Solutions, Bill Robinson oversees disaster relief operations for commercial large loss in the U.S. Bill has seen first hand how water damage can wreak havoc on a home. DKI Services is a remediation and restoration company that offers emergency restoration services for residential and commercial buildings. Some of Bill’s efforts have been nationally and locally recognized throughout the media.