Basement moisture problems are one of the most common challenges in residential construction and remodeling. It’s not uncommon that these issues lead to structural damage, health concerns, and costly repairs for homeowners. Today, these below-grade spaces are often expanded living spaces and are utilized in very different ways than they were decades ago.

Nick DiCello, owner of Ohio State Waterproofing, with almost five decades in the industry, has seen it all. DiCello understands that “much has changed in the way homeowners view their basements in the last 50 years. In today’s market, buyers are looking for homes that are move-in ready and free of major issues. A waterproofed basement increases home market value by an average of 30%, enhancing the property’s appeal to potential buyers.”

DiCello continues, “For homeowners, investing in basement waterproofing not only means an expanding living space, but also a way to reduce future costs related to water damage, such as foundation repairs, mold remediation, and replacement of damaged belongings.”
For contractors, managing moisture in basements is a crucial aspect of building design, renovation, and long-term maintenance. This article provides a detailed overview of moisture management strategies, from identifying moisture sources to implementing effective solutions and offering increased value to customers.

Identifying The Source
Moisture intrusion in basements can occur through several pathways. It’s essential to not only identify the sources of moisture but also the various states of matter in which water exists in order to better design and implement effective solutions. Andre Lacroix, vice president of EZ Breathe Ventilation Systems, points out “The industry is changing, more waterproofing contractors recognize the need to address moisture in all its forms in order to offer a comprehensive waterproofing solution.” The main sources of moisture for a home include:

1. Groundwater Seepage: Water from the surrounding soil is one of the most common causes of basement moisture. Water from rainwater or groundwater seeps through cracks, porous concrete, or poorly sealed joints in the foundation in its liquid state of matter.
2. Condensation: Basements are sub-terranean environments surrounded by cool, moist soil. When the basement air meets the foundation walls there is often a temperature variation that causes condensation. This water, moisture in liquid form, can also occur in other areas where warm meets cool besides the concrete walls like on the metal pipes, duct work, hot water tanks, etc., leading to dampness, rust, and potential mold growth.
3. Plumbing Leaks: Leaking pipes, whether from the HVAC system, plumbing fixtures, or the washing machine, can introduce unwanted moisture into the basement environment that can be both liquid water from leaks and water in its gaseous, vapor form due to evaporation.
4. Humidity: Basements, by their very nature, experience higher humidity or water vapor, due to their location below the ground. This water vapor, without proper ventilation, becomes trapped in the basement air increasing the risk of mold, mildew, and other moisture-related issues.
5. Improper Drainage Around the Foundation: If the ground surrounding the foundation is improperly graded, or if gutters and downspouts are blocked, liquid water may pool near the foundation and seep into the basement. This water intrusion can cause foundation decay, mold, dry rot and contribute to high humidity.

Best Practices for Prevention
Once the sources of moisture are identified, a comprehensive plan to manage and mitigate these issues can be implemented. The strategy for total basement moisture management is best divided into prevention methods, redirection mechanisms, and remediation measures. A comprehensive waterproofing solution must include all of these. (See Water Control vs. Waterproofing sidebar)

1. External Solutions: Preventing Water Entry
   External moisture management is critical for preventing water from entering the basement in the first place. The focus of the project should be on improving the home’s exterior drainage and effective waterproofing.
   • Proper Grading: Ensuring that the ground around the foundation slopes away from the home is one of the most effective ways to prevent water from pooling near the basement. The soil should slope at least 6 inches for every 10 feet of distance away from the foundation. Be sure that landscaping features, such as flower beds or retaining walls, do not interfere with proper grading.
     Gutter and Downspout Main-tenance: Clogged gutters are a common culprit for water intrusion into basements. Regularly cleaning gutters and ensuring that downspouts are positioned to direct water at least 4 to 6 feet away from the foundation is a critical component to preventing water entry into the basement. Downspout extensions and splash blocks are useful tools in directing water further away from the home.
   • Exterior Waterproofing: Applying a waterproofing membrane to the exterior foundation walls is a key preventive measure creating a barrier that helps block water from seeping through the foundation. These membranes are liquid-applied or sheet-applied waterproofing products offering flexibility depending on the project’s needs.
   • Gravel and Drains: Installing both gravel and drains around the foundation is an effective way to manage groundwater. French drains are perforated pipes installed in gravel trenches that redirect water away from the foundation. It may be required by local codes to connect this kind of external system to a storm drain. This outside drainage strategy, when properly employed, is critical to keeping liquid groundwater from entering the basement.
2. Internal Solutions: Managing Liquid, Humidity & Condensation
   Moisture enters through the walls and floor and can also accumulate in the basement due to condensation and high humidity levels. Lacroix explains, “The laws of thermodynamics are to blame because wet moves to dry. The moisture in the soil surrounding the basement walls gets absorbed into the relatively drier air space inside the basement.” Water, in its vapor form, gets absorbed by the basement and is referred to as humidity. Humidity can be remediated by focusing on ventilation, dehumidification, and insulation.
   • Internal Gravel and Drainage: Like the outside drainage system, internal French drains will allow any groundwater from under the walls and floor a pathway other than bubbling up through the walls or floor. Water will flow the path of least resistance into the drain and with the help of a sump pump, redirected up and away from the basement. There is quite the debate regarding sealing up/over these drains. However, allowing basement air to communicate with a drainage system is not a complete waterproofing solution as this allows moisture to enter the basement. (See more in the water redirection vs waterproofing sidebar) Chad Bradley, production manager for Ohio State Waterproofing explains, “Inside drains can be a great secondary protection method, especially when there is a high-water table to address the hydrostatic water pressure, but as a stand-alone system, it does not proof the basement from water.”
   • Ventilation: Adequate ventilation is crucial for controlling moisture levels in the basement. Trapped basement air gets stale and damp in the below-grade environment. Ensuring proper venting to allow for the circulation of fresh air is recommended by the US EPA. Andre Lacroix, adds “the EPA not only lists ventilation as a key strategy for combating polluted indoor air, but also suggests 6 to 8 air exchanges per day to combat indoor pollutants to create a healthier home.” A mechanical ventilation system provides a path of escape for the stagnant basement air and removes the humid air from the basement creating the much-needed air exchanges in that space. Lacroix continues, “Ventilation is integral to a complete basement waterproofing solution as it addresses the removal of water in its vapor form along with other airborne toxins, pollutants, and allergens lurking in basements.”
   • Dehumidifiers: A basement dehumidifier can be an effective solution for controlling excess moisture in the air. Recommending a dehumidifier that is appropriately sized for the basement and suggesting regular maintenance to ensure the system continues to function properly is critical to the success of this solution. In some cases, a whole-house dehumidification system may be a better solution than single-room units.
   • Insulation: Uninsulated basement walls are more susceptible to temperature fluctuations, which can cause condensation when warm, moist air meets cooler surfaces. Installing rigid foam board insulation on basement walls can help prevent condensation and improve overall energy efficiency. However, it is important to ensure that insulation is installed correctly and is part of a comprehensive waterproofing solution.
   • Vapor Barriers: Installing vapor barriers on basement floors and walls can prevent moisture from the ground from rising into the basement. A minimum of a 6-mil polyethylene plastic sheet is commonly used as a vapor barrier on floors. These barriers can prevent moisture from migrating into the basement, reducing the chances of mold and mildew growth.
   • Foundation Sealing: Before applying waterproofing treatments, the foundation should be inspected for cracks, joints, and other potential entry points for water. Cracks can be sealed with epoxy injections or polyurethane foam, while joints can be treated with high-quality sealants to prevent water infiltration.
3. Remediation: Addressing Existing Moisture Problems
   In many cases, moisture problems may already exist in the basement.
   • Mold Remediation: Mold growth is a significant concern in basements, even in those with water control systems and is a sign of underlying source of untreated moisture. Chad Bradley, Production Manager at Ohio State Waterproofing, warns, “You might not see liquid water, but the moisture vapor can lead to mold, odors, rust, etc. because, unlike waterproofing solutions, a water control system invites the water into the foundation.” A thorough inspection to identify underlying sources of moisture, especially areas with visible mold and musty odors is a must for anyone working in a basement. Using proper safety equipment, mold can be removed through a combination of chemical cleaners and physical cleaning methods. In severe cases, the removal of drywall or insulation may be necessary. Lacroix explains that “anything more than 10 square feet of visible mold should be remediated by a mold professional according to the current US Environmental Protection Agency’s guidelines.”
   • Waterproofing Repairs: If the basement already shows signs of water damage, identifying the source of the moisture is the first step, employing the various strategies mentioned above to properly waterproof is the best long-term solution. This could involve fixing leaks in the foundation, repairing or replacing plumbing, or addressing poor grading or drainage systems. James Ketterer, president of Value Dry Waterproofing, says, “This can directly translate into a higher asking price when it’s time to sell the home.”
   • Sump Pump Installation: Sump pumps are essential components for a complete waterproofing solution and for homes located in areas with high water tables and those prone to flooding. Sump pumps should always be installed in the lowest part of the basement floor, ensuring they have an adequate discharge path. Backup systems, such as battery-powered sump pumps provide additional protection in the event of a power outage.
   • Pipe Insulation: Pipes in basements are often exposed to cold temperatures, which can cause condensation when warm, humid air comes into contact with the cold surfaces. Insulating pipes with foam or fiberglass insulation is an effective way to prevent this problem.
4. Long-Term Maintenance and Monitoring
   Moisture management doesn’t end once the basement is dry, emphasizing the importance of long-term maintenance, regular inspections, proper landscaping, and timely repairs to plumbing and drainage systems can prevent moisture problems from recurring. Annual maintenance programs, Ketterer says, “are smart to maintain your dry basement peace of mind. It’s amazing what we find in our annual maintenance inspections, bouncy balls, unplugged pumps, tripped breakers, covered drains, and more, that left unattended would wreak havoc for our systems and customers.” Additionally, the installation of moisture sensors or a basement monitoring system can help homeowners detect potential issues before they become major problems.

Difference Makers Adding Value
Effective and comprehensive moisture management in basements is critical for protecting the structural integrity of a home and ensuring a healthy living environment. Ketterer adds, “Homes with waterproofed basements often benefit from lower insurance premiums due to the reduced risk of water damage, some lenders view waterproofed homes as safer investments, which can make obtaining a mortgage easier for potential buyers.”

As a contractor, understanding the various sources of moisture and the strategies to manage them is vital to delivering quality work and ensuring customer satisfaction. By implementing proper grading, waterproofing, ventilation, and plumbing solutions, contractors can help homeowners avoid costly repairs and preserve the long-term value of their property. Through proactive moisture management and ongoing maintenance, you play a crucial role in maintaining dry, healthy basements for your customers for years to come!