Basement waterproofing is the answer to any homeowner’s nightmare of a leaking, damp, or flooded basement. Even if a basement does not have a water problem today, most will develop leaks and moisture problems sometime in the future. Considering the inevitable, prevention is the cheapest alternative in the long run, instead of paying high repair bills later.
Ideally basement waterproofing should be done during the construction of a new home. However, older homes basements were sealed with tar-based solvents that quite often only last approximately 10 years or so. These tar-based materials eventually dry and crack, allowing water to seep through.
Modern technology has developed are longer lasting solution today, a membrane layer made of polymerized asphalt. If cracking occurs in the wall, this material stretches across the crack to maintain waterproofing integrity. For those homes without this membrane, there are several alternatives to prevent or control water leaks.
Waterproofing Systems: Methods for Controlling Water Leaks
Basements leak because water collects around a home’s foundation causing a buildup in hydrostatic pressure that forces water through cracks, normally along joints where the floor and walls meet. Floors rarely leak unless there are cracks.
The following are several types of basement waterproofing systems that offer different solutions and offer various levels of return on investment.
- French Drain System – this is a system that is buried along the leaking perimeter walls below the basement floor. The French drain consists of a perforated plastic pipe that is connected to a sump pump. The pipe is recovered with cement leaving weep holes that collect water seeping into and through the basement walls.
- Hollow Baseboard Molding – the hollow PVC baseboard is glued with waterproof epoxy along the joint where the wall meets the floor. The hollow channel created by the baseboard collects seeping water through weep holes and sends it to a sump pump. The hollow baseboard system can save hundreds of dollars over the French drain system.
- Sump Pumps – collect water that builds up around the foundation through a series of pipes under the basement that are connected to perforations in the sump pump well. This system relies on the buildup of hydrostatic pressure to force water into the sump pump well. This system is limited in its area of coverage, which often requires more than one sump pump system in a large basement.
- Interior Sealants – this is technically a water sealant application that is spread on the interior walls and floors of a basement to help control dampness that often results in mold and mildew problems. A good waterproofing sealant is often used to support the other three systems above.
- Humidifiers – provide extra support for interior wall sealants to help control moisture and dampness in a basement. Humidifiers are not good for basements that actually leak water through cracks in walls.
- Ventilation System – sometimes the water problem is due to condensation due to poor ventilation of the basement. Installing a basement ventilation system often corrects this problem.
The following are common problems, along with tips for frequent solutions.
- Wall Seepage or Condensation – if the source of water cannot be determined, place a piece of aluminum foil on the wall and seal all edges. Wait 24 hours and check. If water is on the inside of the aluminum foil it is seepage through the wall. If water is on the outside, it is due to condensation as a result of poor ventilation.
- Gutter Downspouts Cause Pools of Water to Collect Near Basement Walls – this collection of rain water saturates the soil next to the basement walls causing water seepage or leaking through cracks. This is corrected by adding three to six foot extensions to the bottom of downspouts to move water away from basements.
- Flat Lawns – or lawns that slope toward the home tend to collect water around basements, causing leakage and seepage through basement walls. The solution is to slope the lawn away from the home. If this is not practical, dig a drainage ditch along the problem area and insert a perforated plastic pipe surrounded by rocks. Now water is drained away from the basement.
- Shrubbery – if the shrubbery is overgrown or dense around the home, it may cause water to collect around the basement area. This happens because the sun cannot reach the ground to dry it out. The correction is to thin the shrubs or use alternative materials to allow the sun to evaporate the water and keep the ground dry.
David R. Wetzel - Dr. David Wetzel's experience includes more than 25 years in continuing, adult, and teacher education.
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