Waterproofing Educational Content
CAUSES OF WATER PROBLEMS
Basement and crawl space water problems are usually caused by hydrostatic pressure. This means that water in the soil pushes against the walls or floor of the basement or crawl space. Eventually, water will leak into the space. Hydrostatic pressure can be caused by poor grading, defective or clogged gutters and downspouts, and failed footing drains. A high “false” water table can also cause hydrostatic pressure. This happens when the water table is higher than your foundation
Poor grading. With proper grading, land slopes away from the house. In some cases, however, the lot may have been poorly graded when the home was built. Soil erosion may have also changed the terrain. Over time, the grading can also shift as loose dirt settles. Landscaping and growing trees can also cause grading issues. Poor grading can route water directly to your foundation, which can cause leaks. You’ll need to have the yard regraded to fix this issue.
Defective gutters and downspouts. Gutters and downspouts carry water away from the house and its foundation. When they’re clogged or incorrectly installed, gutters and downspouts can let water get too close to the foundation. Overflowing gutters and downspouts are a common cause of foundation leaks.
High “false” water table. The water table is the depth at which water saturates the soil. The natural water table is usually far below the house. However, foundations are sometimes built into excavated ground. This means that the foundation is surrounded by loose soil. Water collects easily in this soil, which creates a “false” water table. That false water table can rise above the foundation with excess rain and runoff. Poor drainage can also contribute to the problem. When this happens, water seepage is often the result.
Footing drain failure. Drainage systems can fail over time as silt settles into them and creates clogs. This can happen to any footing drain system installed around a foundation. Footing drain failure leads to the buildup of hydrostatic pressure and then to leaks.
FIXING THE PROBLEM
Interior drainage system. Installing an interior drainage system is an involved process. The crew will remove concrete around the inside edge of the basement floor. Then, they’ll install the drains. The last step is replacing the concrete that was removed. Many interior drainage systems also involve the installation of a sump pump. If your system includes a sump pump, have it inspected and maintained annually. Sump pumps do not work without a power source. If you have frequent power outages, ask your waterproofing contractor about a battery-backup sump pump.
Exterior drainage system. A wall and footing drainage system funnels away water in the soil, which eliminates hydrostatic pressure. These systems are installed below grade, around the outside of your foundation. Before installation, the crew should apply a waterproofing sealant to the outside of the foundation walls.
Injection method. The injection method seals cracks in a house foundation with an epoxy or polyurethane material. These materials expand, which seals the crack and keeps water from coming in. Once the entire crack is full of epoxy or polyurethane, the repair is complete. The injection method isn’t a suitable fix for all types of water-related problems. A waterproofing contractor can tell you whether injection will work for your situation.
Gutters and grading. Problem gutters and poor grading need to be fixed. If your gutters overflow during storms, they’re dumping gallons of water close to your foundation. Your gutters could be clogged or too narrow. It’s also possible that they were installed with an inadequate degree of slope. Have your gutters cleaned at least twice per year to keep them clear. Gutters that are too narrow or poorly installed will likely need to be replaced. Poor grading means that the ground slopes toward your house instead of away from it. This can route water directly to your foundation. You’ll need to have your yard regraded to fix this issue.
Foundation cracks. Water enters a house most often at the cold joints between the basement wall and floor and the footing. Shrinkage cracks and pipe penetrations are also common spots for water intrusion. Porous cement block walls and mortar joints are especially susceptible to leakage. These cracks need to be fixed to prevent ongoing problems.
SEALING THE CRAWL SPACE
Ventilation used to be the industry standard for controlling crawl space moisture, mold, and mildew issues. In fact, crawl space ventilation was written into many building codes. The US Department of Energy later funded a study that found that a sealed and conditioned crawl space is better than a vented crawl space. Sealed crawl spaces have fewer issues with fungus growth, humidity, and energy consumption.
Installing a waterproofing system is the first step in correctly sealing a crawl space. Then, all utility vents and penetrations need to be sealed off. The walls and floors should be covered in a thick vapor barrier. The next step is installing insulation between the floor joists. Finally, a dehumidifier or other humidity management system must be installed.
Waterproofing is a cyclical business. During and after especially wet weather, the best waterproofing companies can get backed up. Call in the professionals at the first sign of a possible water issue. Don’t wait until you have a disaster on your hands. And once your waterproofing system is in place, stay on top of maintenance. These systems can fail if they aren’t inspected and maintained regularly. Waterproofing pros know how to maintain their products and protect your investment.