When it comes to keeping water out of your basement or crawl space, you'll usually have several options, each offering varying levels of effectiveness, longevity, and cost-effectiveness. While all of these choices can work well if implemented by qualified installers, there still tends to be a hierarchy of effectiveness between them.
In general, exterior solutions are better than interior solutions, and drainage is better than sealants, epoxies, or membranes. In practice, this means that an exterior (or perimeter) drainage system will often provide the best results, especially when paired with exterior coatings. What makes these systems so much more effective than other options? Keep reading to find out.
How Water Intrusion Works
Water typically enters your basement, crawlspace, or ground floor (in homes with slabs) in one of two ways: seepage or traveling through cracks and joints. Concrete is porous, so moisture can saturate the wall and make its way through a seemingly solid surface. This situation often occurs when there's a large amount of hydrostatic pressure outside the wall.
Cracks and joints are a more common method of entry. Water will often enter homes where the basement wall meets the footer, since this joint may provide enough of a gap for water to seep in even with a relatively low amount of pressure. If water accumulates in the soil around your basement, you may notice water beginning to enter at the base of your walls.
Interior sump pump solutions often target this latter case. A drain installed along the edges of the basement interior collects any water that enters the space and redirects it to the sump pit. The pump can then remove the water. While this interior drainage solution effectively keeps your floor dry, the presence of moisture in your basement can lead to higher humidity and other issues.
The Benefits of Perimeter Drainage
Perimeter drainage systems (often known as French drains) utilize perforated plastic pipes installed along your basement footer. These pipes collect water from the surrounding soil and redirect it to a safe drainage location. The primary advantage of perimeter drains is that they work to relieve both hydrostatic pressure and water intrusion.
By installing a drain in line with your home's footing, the drain system can help ensure that the water level does not reach the joint between the footing and your basement walls. This drainage prevents the most common source of leaks, helping to keep your basement dry without allowing water inside. This design also helps promote drainage in the soil around your basement, relieving hydrostatic pressure.
Since drainage systems can't remove all water from the soil, many homeowners also opt to install exterior damp-proofing or moisture barriers. These barriers help to prevent moisture in the soil from seeping through your basement walls. When installed together, these two systems provide the best approach to protect your foundation and keep your basement dry.
Reach out to a residential waterproofing company to learn more.