While there are many reasons why a basement might leak the most common causes are related to construction techniques used when your home or building was originally built. Construction techniques have evolved over time to the point that new construction, completed by a reputable contractor, will be highly effective in keeping your basement dry. This is of little help to the owners of older homes and structures that were built before modern construction practices were in place.
Many basements leak because moisture seeps through basement floors and/or walls through tiny fissures in the concrete that are called “capillaries.” If this is the cause of your problem, the application of waterproofing paint or other compounds to your basement floor and interior walls will likely solve the problem. These materials penetrate an inch or more into the concrete to seal the capillaries that are allowing moisture to seep through.
These waterproofing products are available at your local hardware or building supply store. Be sure to read the labels of these products carefully to make sure they are suited to your particular problem and that you know how to apply them, properly.
If your basement still leaks after the application of these waterproofing products, then more serious issues are in play. In this case, you would be well advised to contact a professional contractor such as Jersey State Waterproofing so that they can evaluate your problem and recommend an appropriate solution.
Visit http://www.waterproofing.org/tips.html for more information about the various causes of leaky basements.