If you want a dry crawl space and a sound foundation, you must have an adequate foundation drainage system. The water content in the soil surrounding your house can fluctuate seasonally. There is always a point at which you can dig and hit water. Geologists often refer to this as the water table. This water table rises and falls in response to the amount of precipitation in any given time period. The water table in many parts of the country can rise to within a few feet of the surface during wet spells. Water will take the path of least resistance. If there is no exterior waterproofing, water can go sideways through a crack in your foundation, or it can go down alongside your foundation into a pipe. I’m sure that you will agree that it is a better idea for the water to go down into the pipe.
Exterior foundation drainage systems, which are installed properly, serve an important roll. Foundation drain tile systems are the means by which groundwater can be transported away from your basement. Keeping water from pooling around your foundation is the most important step in keeping you home dry and your foundation stable. Water that is trapped around or under your home is the number one reason so many foundation repairs are needed across the country.
Interior drainage systems work extremely well for many customers. Depending on your circumstances, interior drainage may be an effective solution. Many water control system companies claim to be waterproofers and only offer this method as a solution to every crawl space water problem. If a company proposes opening the floor on the inside for any reason, they are offering an interior drainage system. Only an exterior excavation to the footer or bottom of the foundation accomplishes waterproofing. Everything else is water diversion. Never only contract for an interior water control system if dampness, seepage, and or cracking on the walls are your concern, as this may result in further damage to your foundation. In combination with exterior waterproofing and or structural repairs interior drainage can be very effective.
Related: Drainage solutions
Be very care of companies that only offer and push interior drainage as the only solution to your water problem. While a good interior drainage system does a very good job of removing water from under your slab and diverting water vapor that penetrates walls they do nothing to solve the original problem of water forming around your foundation causing hydrostatic pressure and potential structural damage.