One of the most basic concepts homeowners must grasp is this: imagine your home sits on a giant sponge! The soil around your home will absorb moisture, and this water continues to spread, seep and move beneath the surface! Water does not stop at the wall of your home, but continues to move at some depth below the surface (if you’re lucky!) For this reason, purely external ‘fixes’ such as grading frequently improve but do not eliminate crawl space issues!
In most areas of the Country the ground releases moisture (humidity) into the air. Especially in Crawl Spaces that do not circulate well, this humidity can sit in the air absorbing into the floor system and insulation and be a major contributor to the problems in the crawl space.
Even dusty, dry dirt when it’s not covered by a plastic can be releasing a tremendous amount of moisture. For those crawlspaces that have mud, running or ponding water, the problem is only that much worse!
As you’ll see below, there can be indicators of water backing-up against the foundation wall. This water, soaking in from Rain, or from up-slope lots, hits the foundation and walls of your home and eventually seeps beneath the footing. If you’re very lucky, this water remains beneath the surface – other times it is substantial enough to begin saturating the floor and flowing to the low point. Regardless, this situation allows for excessively wet soil beneath the footings of your home, adding to the chances of potential long-term foundation issues (such as cracking, settling, etc.)
It’s important to note that even very level lots can have water issues in the crawl space! Again, imagine your home sits on a giant sponge! If water drips on the exterior, it spreads under the home and eventually begins to rise!
One key indicator to look for is dirt that is either moist or a different color or texture against the foundation wall on the inside of the crawl space. As water soaks beneath the footing, it most often immediately rises up beside the foundation wall – so an otherwise dry crawl space can have a ‘picture frame’ of moist or wet soil at the walls, about 6″-12″ away. It’s easy to imagine your foundation sitting on muddy soil when it’s wet on both sides!