When there is water or moisture entering a basement or crawl space, most likely the problem is that the original drain system was not designed or installed correctly.
Many homes have a little to no gravel against the home. Many contractors completely backfill a home’s crawlspace with red clay soil, which is free and abundant in South Carolina. Red clay soil can hold moisture for an extended period of time against the foundation of your basement or crawl space making it unwise for backfill. Red clay will allow silt to enter the drain pipes and eventually clog up a working drainage system.
The best resolution is excavating (digging out) the earth against the home. You must be aware that when digging, any landscaping close to the dig will likely die. Sidewalks may need to be removed and heating and air-conditioning systems removed temporarily and then reinstalled.
The earth needs to be removed to below the footing if at all possible. Starting at the deepest point, we dig below the footing to a lower relieving drain point somewhere on your property. The relieving point of your drainage system should be open to sunlight and uncovered so that gravity will be able to drain any water away that reaches the walls and footings to an area on the property that is lower than the footing.
Once drainage and gravel is completed, waterproofing of the walls needs to be considered. The walls will need to be cleaned and then a complete waterproofing application applied to the wall. There are many types of products that can be applied to the exterior walls of the home. Choose a long lasting quality product and expect to do three coats. BASF produces some of the best waterproofing materials. Next, we will add an exterior waffle board material to go between the waterproofing and gravel. Gravel should always be the choice of backfill. We will use gravel 1 to 2 feet away from the wall all the way to the top of the wall. Water will run through the gravel straight to the drain pipes and then off of your site. Filling completely with gravel allows no hydrostatic pressure and creates a drain sluice that can last indefinitely when done correctly.
Before starting an excavating project, whether it is doing it yourself or hiring a contractor, you must call to have all utility services (Power water cable gas etc.) marked. In South Carolina, call 811 or 1-888-721-7877. It is the law, it is free, and it may even save someone’s life.