If you own a home or for that matter, any other building with a basement, chances are you've had to deal with one kind of water problem or another. Any structure built below the ground level must do something to keep ground water out. Basement waterproofing is a body of knowledge and techniques that encompass solutions to every basement water problem from occasional moisture to free standing or flowing water. Whether you're a do-it-yourself person or someone who prefers to contract with professionals, it pays to equip yourself with the right knowledge so that you can make informed decisions.
The first step toward a waterproof basement is to fully understand the problem. All ground naturally contains some amount of moisture. The amount of moisture (or water) in a particular spot will vary at any given time but over time, ground water will always be present to some extent. Since a basement is built below the ground level and therefore displaces the ground around it, the water in the surrounding ground is propelled by natural forces to enter that basement. Contractors will often use the term hydrostatic pressure to describe this phenomenon. In this context, hydrostatic pressure refers to the tendency of water to spread out. This tendency is created by the effects of gravity. All water, including ground water, is under the influence of gravity. As gravity pulls water downward, the water below is pushed aside by water above. If you imagine pouring a class of water onto the floor, it doesn't pile up as sand would for example, but rather it spreads out. Water in the ground is actually no different. As gravity exerts its influence, water at all levels is under some pressure to spread out. Your basement is a cavity in the ground containing less or no water. Therefore the water surrounding it is compelled to enter.
Although the use of the term: hydrostatic pressure is technically accurate to describe the reason water enters a basement, it should also serve as a warning sign. Some disreputable contractors will use technical terms like this as high pressure sales tactics with the goal of convincing customers that their problems are much more serious and thus require more expensive resolutions. Again, this is where it pays to arm yourself with knowledge. While the reason water enters your basement can be explained with a scientific term like hydrostatic pressure, the solution to your water problem is often much more straightforward and therefore, much more affordable.
If your problem is persistent moisture that causes mold and musty odors, your solution might actually be simply to employ a dehumidifier. In more severe cases, a moisture sealer applied to your basement walls will also solve the problem.
If your problem is more severe, such as persistent seepage or the accumulation of standing water, your best solution is probably going to be a method or combination of methods falling into three categories: barrier systems, drainage systems, and diversion systems.
A barrier system is one that is designed to prevent outside ground water from entering the basement in the first place. Barrier systems can be very simple and inexpensive, like a sealer applied to the inside surface of the basement walls. There are also more expensive and involved barrier systems such as polymer-based sealants applied to the outside of basement walls. The main source of the added expense is excavation to expose the exterior wall surfaces.
Drainage systems may operate inside or outside of the basement walls. While inside drainage systems can't technically be described as waterproofing, they are effective means of dealing with basement water. A drainage system is designed to drain water from the ground immediately surrounding the basement walls to a remote location. In other words, the water is given another place to go besides accumulating in the basement.
Diversion systems operate exclusively outside of the basement walls. Virtually every home ever built has a diversion system: the rain gutters and spouts. A diversion system collects the rainwater that accumulates on a structure and diverts it away from the ground immediately surrounding the basement walls. Although virtually every home has gutters and spouts, they can very often do an inadequate job of diverting the water far enough away from the basement walls. Homes are typically built with rain spouts draining into underground pipes leading to public storm drains. When functioning properly, these systems work well. However, over time the pipes can become clogged or broken. Often times, homeowners will simply put an elbow joint at the bottom of the spout thinking that it is sufficient just to get the water flowing away from the house. However, this is usually not sufficient.
The solution to any particular basement water problem will vary in technique and expense. Regardless, it pays to increase your knowledge of basement waterproofing. In the age of the internet, basement waterproofing information is readily available. Arming yourself with knowledge beforehand and making informed decisions means you're much more likely to solve your basement water problems quickly. That means saving time, hassle, aggravation, and money.