First, Find The Problem
Water and moisture in basements come from two main sources. One source comes from humidity indoors which condenses on cold surfaces. Like water, droplets form on a cold iced tea on a humid summer day. The other is water vapor which comes from outside the house. Melting snow, rainwater, and groundwater can saturate the soil around your home foundation. Eventually, the water can leak in. Water leaks through cracks and porous concrete or masonry walls. To discover what is causing the moisture problem, you can tape aluminum foil to your basement wall. After a few days inspect the foil. If you see moisture on the outside surface of the foil, this indicates high indoor humidity. If you find moisture behind the foil, it means moisture is leaking through the walls.
Remove Excess Humidity
To dry out your basement, eliminate the source of the humid air. Seal leaky dryer vents with foil tape. Be sure to not use duct tape, it will eventually fall off. Keep your basement windows closed during humid weather.If you are really serious about removing moisture, add a vent fan to your basement bathroom. If you’re still getting condensation on cool surfaces, run a dehumidifier to lower the indoor humidity.
In cold climates, insulating basement walls can save energy and reduce your heating bill. However, don’t cover the walls with insulation if water is leaking in from outside — you’ll create a potential mold problem.
Holes and Cracks
Holes and cracks in your home’s foundation can let moisture and water seep into your basement. Plugging the holes alone generally won’t solve your basement leak problems. However, hydraulic cement works well for patching holes in a foundation because it can set up even underwater. An advantage is that this material expands as it sets to seal the hole and lock the plug in place. If you do this yourself, use a cold chisel or an angle grinder fitted with a masonry-cutting disc or diamond blade to enlarge the hole or crack into an inverted “V,” with the narrow part of the “V” on the surface of the wall. This can be a complex process, it might be a good idea to hire a basement repair company.
Condensation dripping from cold pipes can contribute to basement water problems. To solve this problem, cover cold water pipes with foam pipe insulation to stop the condensation.
Keep Water Away From the Foundation
If your basement leaks after big storms, heavy rains or snow melts, be sure water is diverted away from your foundation. It’s common for the soil alongside your house to settle over time. This creates a natural moat which collects runoff and directs the water down your foundation wall and eventually into the basement. Believe it or not, lawn edging and gravel along your foundation can make the problem worse. Solve this problem by creating 5-7ft.-wide slope which drops about 4 inches away from the house foundation. For more coverage slope the soil with a layer of 6-mil poly. Then hide the poly sheet with mulch, gravel or a layer of soil covered with grass. This keeps water from soaking in and near the foundation.
Gutters and Downspouts
If you don’t have gutters, consider adding them. Gutters will catch the rain and channel it to the downspouts, which direct it away from the house. This is a very common problem which causes water damage. Whether you’re installing new gutters or already have them, be sure the downspouts have 4- to 6-ft. horizontal extensions to move the water away from your house.
Waterproof the Walls
Waterproofing materials which go on like paint fill the pores of the concrete or masonry walls. This prevents water from leaking into your basement. To be effective, these coatings must be applied to bare concrete or masonry walls. It’s important to remove loose material with a wire brush. Clean off white powdery efflorescence with masonry cleaner. Make sure to follow safety and application instructions carefully. A common mistake when non-professionals use masonry waterproofing products is to spread them too thin on the walls. The goal is to fill every small hole to create a continuous waterproofing membrane. You might consider adding a second coat after the first dries.
The best fix is more permanent for chronic basement leaks. Consider installing a drainage tubing below the basement floor which is connected to a sump pump system. You can install a system yourself, however breaking a concrete floor, burying the tubing, and patching the floor is a lot of hard work. Materials to do an average basement tend to cost over $1,000. Expect to spend much more for a professionally installed basement.