Water
Water can seep into a crawl space from just about anywhere. If your space has a dirt floor, it can even come up through the ground. Without proper ventilation, this water stays sitting in the crawl space, keeping it damp. Dampness leads to mold, mildew and rotting wood. The best solution is often to install a drainage system followed by a concrete crawl space liner. This allows for improved exterior drainage and a concrete shell that keeps water out.
Critters …show more content…
To keep them out, you'll need to look for any cracks or crevices and seal them with caulk. A vapor barrier will also help slow the invasion of unwanted critters, as will the concrete liner mentioned previously. This works because moisture is attractive to insects and other pests who need a water source close to their nest to survive. A lack of water makes your space less attractive. Of course, it's not always possible to exclude all unwanted guests all the time, so be sure to have an exterminator check your space periodically and address any issues that he finds.
Mechanical