How Does Interior Basement Waterproofing Work?

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You may want to consider interior basement waterproofing if you desire a dry basement to use for storage or remodel into an entertainment area or family room.

Water intrusion of any kind in the basement of your home can be disastrous. Therefore, consider contacting a basement waterproofing professional to examine your basement at the first sign of cracks and leaks.

Wet or Leaky Basement Problems

A wet or leaky basement is a significant concern for any homeowner. What might appear to be a slight trickle or leakage can be a warning sign requiring instant action. The presence of moisture in the basement area of your home can lead to an array of expensive and time-consuming repairs.

From the formation of toxic molds to structural damage to your house, water in the basement can turn out to be a significant issue. What you need is waterproofing to solve your problem. We will help you discover some secrets behind basement waterproofing and what measures to take if you ever need it.

What Causes a Wet Interior Basement?

basement leakage from corner
Typical basement leakage from the corner of the room.

When you wish to understand the importance of keeping your basement dry, it is vital to know what exactly causes moisture. Unfortunately, as homeowners, it is essential to note that water has a knack for finding its way into every corner of your home. Because of the basements’ unique construction and nature, the given space is particularly prone to wetness.

Here are some of the primary causes:

Improper Slope:

The ground near the foundation of your home outside should slope away from your home. The slope should not decline towards the home’s foundation. Water accumulation occurs around the house’s foundation when the slope is incorrectly graded. It tends to damage the overall structure.

Improper Drainage & Soil Systems:

When the groundwater and rainwater cannot drain properly, they can make their way into the basement area of your house. Poor drainage systems and weak soil around your home’s foundation are some of the most common causes of wetness in the basement. When the water flow is not directed away from the house, it will accumulate around the foundation, which will flow into the basement’s cold joints, porous walls, floor, and cracks.

Poorly Installed & Maintained Gutters:

Gutters are assembled to direct rainwater away from the foundation of the house. When the gutters are installed improperly or get clogged due to poor maintenance, water will drain toward the home’s foundation – rather than away from the foundation.


Basements are known to be notoriously wet places. In case condensation occurs in your basement, it can lead to the formation of mold and mildew and cause potential damage to an organic surface—especially sheetrock and wood.

Cracks in the Basement:

Cracks on basement floors, walls, ceilings, and around the doors & windows tend to provide the perfect way for water could flow into the basement area from the outside. Water always finds the most accessible paths through the least resistant areas, and cracks in the basement serve as the most natural path for water to get inside.

Hydrostatic Pressure:

Hydrostatic pressure occurs when water accumulates around the foundation of your house. As gravity tends to push down the water, it tries to escape by releasing pressure. As such, the water forces its way into cracks in basement walls and floor or the area where the wall and floor meet. Due to the build-up of intense pressure, foundation cracks can form on basement walls and floors.

Most Common Ways to Waterproof a Basement

Now that you have received an in-depth idea of the common causes of wetness in the basement, it is essential to know how interior and exterior waterproofing works to keep the area dry.

Interior Waterproofing

Do-It-Yourself’ers use quick, simple interior basement waterproofing methods when the first sign of a water leak or crack is visible. A temporary solution for interior waterproofing might include using coatings, sealants, and a dehumidifier to prevent condensation in the basement area.

Exterior Waterproofing

While it is essential to make the interior of your basement waterproof, exterior waterproofing is equally crucial. When dealing with wet basements, most problems usually arise from the outside environment.

Therefore, looking at the exterior waterproofing on the foundation walls is necessary. Exterior waterproofing requires expensive and complicated procedures in comparison to interior basement waterproofing. This approach requires a unique skill set of laborers to help get valuable results. Hiring a contractor with less experience to save some money might cost you bundles of money in the long run.

An excavator digs out a trench around the perimeter of the building to waterproof exterior walls and drain tile.

Exterior basement waterproofing involves excavating the soil surrounding your house’s foundation. It turns out to be a pretty labor-intensive procedure that might require extensive tools & large machinery.

Once the soil around your home’s foundation has been properly excavated, a high-quality waterproof sealant is applied to the exterior walls of your basement. The sealant is usually some polymer-based material meant to last 25 years. In reality, you would be lucky if exterior waterproofing continues to be effective after five years.

The loose backfill soil surrounding your home’s foundation will move up and down, side to side, as the hydrostatic pressure changes during every rainstorm tearing through the waterproofing layers applied during construction. The hydrostatic movement of soil and underground stone will result in the breached waterproofing material. In ideal cases, exterior waterproofing should occur during the house’s original construction. Quickly constructed homes lack adequate protection to fight back groundwater.

Interior Basement Waterproofing Systems

A superficial DIY interior repair and an expensive, short-lived exterior waterproofing is no comparison to an interior basement waterproofing system. We may be biased, but it is the most effective choice of the three methods.

interior basement waterproofing system
Interior basement subfloor drainage is easier to install than exterior drainage and more affordable.

Imagine a waterproofing system that removes water as effectively as an exterior drainage system without the concern of loose, soft soil that surrounds it in the hydrostatic zone, wearing it away. Exterior systems tend to clog with dirt and rocks. There is also a possibility of root intrusion and grading the perimeter again after 8 to 10 years.

An interior system can effectively manage water under your floor by removing groundwater before it touches your floor. Some systems sold by large franchises manage water at almost floor level, defeating keeping moisture out and keeping walls and floors dry. Make sure you get a system that manages water in the proper location under your floor. The beauty is that you don’t lose any of your landscaping outside with an exterior excavation project. When done correctly, most interior systems are installed in 2 to 3 days.

Other usual considerations for interior basement waterproofing are easy and cost-effective for homeowners. Existing cracks or holes in the basement’s floor and walls are sealed and appropriately made watertight. Special sealants, such as hydraulic cement, can waterproof cracks or holes. These solutions are only meant for the short term. It is time to consider a long-term plan.

sump pump installation
A sump pump is part of the interior drainage system. The pump helps to remove collected drainage water.

A sump pump installation is also as necessary as the interior basement waterproofing system. It will remove thousands of gallons of water an hour through a discharge pipe. Some basements don’t require a sump pump station if drain grates are in the center of the basement floor. Those grates have a drainage path below the floor that leads away from the foundation. Sometimes they are not enough to get the groundwater that leaks through the area between walls and the floor.

It comes down to who is selling you a waterproofing system. Currently, interior basement waterproofing is unregulated, so plenty of shady characters are dying to sell you one. First, do your research before anxiously making a decision. If you want to stop your water problem install a robust system that requires zero maintenance. If it requires maintenance and unique flooring, you will be paying for your system for the rest of your life. Install the proper basement waterproofing system in your basement for the best results.

Schedule a free, no-obligation inspection and quote at no cost.